Identifier,"Start Date / Time","End Date / Time",Title,Subtitle,Type,Description,Permalink,"Building Name",Room,"Location Name",Cost,Tags,Sponsors
101534-21801492,"2022-11-29 16:00:00","2022-11-29 17:00:00","Statistics Department Seminar Series: Emily Diana, PhD Candidate, Department of Statistics and Data Science, Wharton School, University of Pennsylvania","""Addressing Algorithmic Bias and Disclosiveness: Minimax Group Fairness and Multiaccurate Proxies for Redacted Features""","Workshop / Seminar","Abstract: While data science enables rapid societal advancement, deferring decisions to machines does not automatically avoid egregious equity or privacy violations. Without safeguards in the scientific process --- from data collection to algorithm design to model deployment --- machine learning models can easily inherit or amplify existing biases and vulnerabilities present in society. My research focuses on explicitly encoding algorithms with ethical norms and constructing frameworks ensuring that statistics and machine learning methods are deployed in a socially responsible manner. In particular, I develop theoretically rigorous and empirically verified algorithms to mitigate automated bias and protect individual privacy.
I will highlight this work through two main contributions. In the first, I discuss a new oracle-efficient and convergent algorithm to provably achieve minimax group fairness -- fairness measured by worst-case outcomes across groups -- in general settings. In the second, I illustrate a framework for producing a sensitive attribute proxy that allows one to train a fair model even when the original sensitive features are redacted or unavailable.
Full text versions of the two papers can be found at https://dl.acm.org/doi/10.1145/3461702.3462523 (“Minimax Group Fairness: Algorithms and Experiments”) and
https://dl.acm.org/doi/10.1145/3531146.3533180 (“Multiaccurate Proxies for Downstream Fairness”).",https://events.umich.edu/event/101534,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
101156-21800885,"2022-11-30 15:00:00","2022-11-30 16:00:00","Department Colloquium | Dr. Willie Hobbs Moore: Reflections on Her Life and Science","Donnell Walton (Corning)","Workshop / Seminar","This colloquium is a hybrid event. It will take place in 340 West Hall and via a YouTube live stream link: https://youtu.be/heYnnM-xC5A.
In 1972, Willie Hobbs Moore became the first African-American woman to receive a PhD in physics, right here at the University of Michigan. On the 50th anniversary of this historic event, I will:
- discuss some of Dr. Hobbs Moore's biographical highlights,
- provide an overview of her dissertation research,
- share some memories of my friendship with Willie and her family before and after her untimely passing in 1994.
",https://events.umich.edu/event/101156,"West Hall",340,"West Hall",,"Physics
Science","Department of Physics
Department Colloquia
Undergrad Physics Events"
101339-21801237,"2022-12-02 15:00:00","2022-12-02 16:00:00","HET Seminar | A top-down dictionary for double holography","Andreas Karch (UTexas)","Lecture / Discussion","Holographic interpretations of Randall-Sundrum (RS) branes provide a laboratory to explore the way quantum information evolves in field theories coupled to gravity. Despite this importance, the holographic interpretation of RS branes in terms of a theory of gravity coupled to a CFT is rather ad-hoc. In this talk, we use top-down constructions of RS branes in order to work out a precise dictionary for this ""intermediate"" holographic prescription, resolving serious causality problems of the naive picture often used in the literature while preserving many of the successes of the RS construction",https://events.umich.edu/event/101339,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics
Science","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
101602-21801565,"2022-12-05 15:00:00","2022-12-05 16:00:00","HEP-Astro Seminar | Evidence for Cosmological Coupling of Black Holes and Its Implications For an Astrophysical Source Of Dark Energy","Kevin Croker (University of Hawaii)","Workshop / Seminar","Observations have found black holes spanning ten orders of magnitude in mass across most of cosmic history. The leading black hole model, the Kerr solution, is however provisional because its behavior at infinity is incompatible with an expanding universe. Recent work on black hole models with realistic behavior at infinity predicts that the gravitating mass of a black hole can increase with the expansion of the universe independently of accretion or mergers, in a manner that depends on the black hole’s interior solution. Here we test this prediction by considering the growth of supermassive black holes in passively evolving elliptical galaxies over 0 < z < 2.5. We find evidence for cosmologically coupled mass growth among these black holes, with zero cosmological coupling excluded at 99.98% confidence. The redshift dependence of the mass growth implies that, at z < 7, black holes contribute an effectively constant cosmological energy density to Friedmann’s equations. The continuity equation then requires that black holes contribute cosmologically as vacuum energy. We further show that, within current observational limits, black hole production from the cosmic star formation history gives the cosmological constant value measured by Planck. We thus propose that stellar remnant black holes are the astrophysical origin of dark energy, explaining the late-time onset of accelerating expansion.
",https://events.umich.edu/event/101602,"West Hall",335,"West Hall",,"Physics
Science","Department of Physics
HEP - Astro Seminars"
101276-21801144,"2022-12-06 16:00:00","2022-12-06 17:00:00","CM-AMO Seminar | Topological Magnetic Defects in Frustrated Magnets","Huibo Cao (Oak Ridge National Laboratory)","Workshop / Seminar","Magnetic domain walls and their crossings as magnetic vortices are typical magnetic topological defects existing in many magnetic materials. While visualizing them and their evolution under field at the atomic level are rarely reported except for magnetic skyrmions. Here I will present the proliferation of topological magnetic defects in a 2D square lattice under field, seen by neutrons.
By introducing Ising spins in a 2-dimensional (2D) bi-layer square lattice, we realized a frustrated magnet where no long-range magnetic order was found upon cooling to 100 mK. Using the local magnetic susceptibility method with polarized neutrons, we revealed canted Ising spins. With this information, we were able to simulate the neutron diffuse scattering patterns observed under selected magnetic fields through machine learning assisted spin Hamiltonian optimization. Our studies revealed a short-range ordered 2D stripe magnetic phase wrapped by domain-wall phases. By applying magnetic field perpendicular to the square-lattice plane, the stripe magnetic phase melts and the condensed domain wall phases form a short-range ordered vortex lattice, so-called magnetic vortex liquid state, at a critical field of 2 T. Further application of the magnetic field to 4 T, makes all of the spins canted to the field direction, i.e., a polarized paramagnetic phase. Here the evolution of stripe phase and domain wall phase can be precisely controlled by a magnetic field and tracked by neutron scattering. A Z4 vortex was found to be originated from two crossed domain walls. While the density of the domain wall and vortices increase with the field and reach their maximum before entering the fully polarized paramagnetic phase.
*The research was supported by the U.S. Department of Energy (DOE), Early Career Research Program Award KC0402020 and used resources at the HFIR and SNS, DOE Office of Science User Facilities operated by ORNL.
",https://events.umich.edu/event/101276,"West Hall",335,"West Hall",,"Physics
Science","Department of Physics
CM-AMO Seminars"
98153-21795649,"2022-12-09 10:00:00","2022-12-09 11:00:00","Statistics Department Seminar Series: Rob Trangucci, PhD Candidate, Department of Statistics, University of Michigan","""Identified vaccine efficacy for binary post-infection outcomes under misclassification without monotonicity""","Workshop / Seminar","Abstract: Despite the importance of vaccine efficacy against post-infection outcomes like transmission or severe illness, these estimands are unidentifiable, even under strong assumptions that are rarely satisfied in real-world trials. We develop a novel method to nonparametrically point identify these principal effects while eliminating the assumptions of monotonicity and perfect infection and post-infection measurements. Furthermore, we show that these results immediately extend to multiple treatments. The result is applicable outside of vaccine efficacy due to the generality of the results. We show that our method can be applied to a variety of clinical trial settings where vaccine efficacy against infection and a post-infection outcome can be jointly inferred. This can yield new insights from existing vaccine efficacy trial data and will aid researchers in designing new multi-arm clinical trials.",https://events.umich.edu/event/98153,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
101308-21801176,"2022-12-12 12:00:00","2022-12-12 13:00:00","Quantitative Biology Seminar | Starling Flocks Seen From Statistical Physics","Tomas S. Grigera (Universidad Nacional de La Plata (Argentina))","Workshop / Seminar","Many animal species move together in groups (schools, herds, flocks) without leaders but displaying complex collective behavior, sometimes visually very striking. This behavior is the emergent of individual interactions, so that the phenomenon can be fruitfully approached from statistical physics. In this talk we shall summarize experimental results on flocks of starlings (Sturnus vulgaris) in the field, and show that it is possible to develop a sensible statistical theory of their collective movement, despite the difficulties related to out-of-equilibrium effects and relatively small system size. We shall discuss in particular the presence of scale-free correlations in speed and velocity fluctuations and their relation to symmetry breaking and speed control mechanisms.
",https://events.umich.edu/event/101308,"West Hall","335 ","West Hall",,"Physics
Science","Department of Physics
Quantitative Biology Seminars"
102479-21804109,"2023-01-06 10:00:00","2023-01-06 11:00:00","Statistics Department Seminar Series: Spencer Frei, Postdoctoral Research Fellow, Simons Institute for Theory of Computing, University of California, Berkeley","""Statistical and computational phenomena in deep learning""","Workshop / Seminar","Abstract: Deep learning's success has revealed a number of phenomena that appear to conflict with classical inuitions in the fields of optimization and statistics. First, the objective functions formulated in deep learning are highly nonconvex but are typically amenable to minimization with first-order optimization methods like gradient descent. And second, neural networks trained by gradient descent are capable of 'benign overfitting': they can achieve zero training error on noisy training data and simultaneously generalize well to unseen data. In this talk we go over our recent work towards understanding these phenomena. We show how the framework of proxy convexity allows for tractable optimization despite nonconvexity, while the implicit regularization of gradient descent plays a key role in benign overfitting. In closing, we discuss some of the questions that motivate our current work on understanding deep learning, and how we may use our insights to make deep learning more trustworthy, efficient, and powerful.
Bio:
Spencer Frei is a postdoctoral fellow at UC Berkeley, working with Peter Bartlett and Bin Yu as a part of the NSF/Simons Collaboration on the Theoretical Foundations of Deep Learning. He is interested in understanding statistical and computational phenomena observed in deep learning. He was named a Rising Star in Machine Learning by the University of Maryland in 2022, and was a co-organizer of the 2022 Deep Learning Theory Workshop and Summer School at the Simons Institute for the Theory of Computing. He received his Ph.D in Statistics from UCLA in 2021 under the co-supervision of Quanquan Gu and Ying Nian Wu.",https://events.umich.edu/event/102479,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
102480-21804110,"2023-01-10 16:00:00","2023-01-10 17:00:00","Statistics Department Seminar Series: Lizhen Lin, Robert and Sara Lumpkings Associate Professor, Department of Applied and Computational Mathematics and Statistics, The University of Notre Dame","""Adaptive variational Bayes: optimality, computation and applications""","Workshop / Seminar","Abstract: In this talk, I will discuss adaptive statistical inference based on variational Bayes. Although a number of studies have been conducted to analyze theoretical properties such as posterior contraction properties of variational posteriors, there is still a lack of general and computationally tractable variational Bayes methods that can achieve adaptive inference. To fill this gap, we propose a novel adaptive variational Bayes framework, which can operate on a collection of models. The proposed framework first computes a variational posterior over each individual model separately and then combines them with certain weights to produce a variational posterior over the entire model space. It turns out that this combined variational posterior is the closest member to the posterior over the entire model in a predefined family of approximating distributions. We show that the proposed variational posterior achieves optimal contraction rates adaptively under very general conditions and attains model selection consistency when the true model structure exists. We apply the general results obtained for the adaptive variational Bayes to a large class of statistical models including deep learning models and derive some new and adaptive inference results.",https://events.umich.edu/event/102480,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
102429-21804043,"2023-01-11 10:00:00","2023-01-11 11:00:00","Special Physics Department Seminar | Searching for Uncovered and Unexpected New Physics at the Energy Frontier","Julia Gonski (Columbia University)","Workshop / Seminar","Join the Seminar Zoom Link: https://umich.zoom.us/j/92784237259
The 2012 discovery of the Higgs boson with the Large Hadron Collider (LHC) was a groundbreaking achievement for high energy physics. Remaining puzzles such as dark matter confirm the need for beyond the Standard Model physics, and the Higgs boson can be used as a compass to determine its nature. This talk focuses on novel searches for new physics with the ATLAS experiment on the LHC, specifically for long-lived particles and heavy resonances. Such signatures make use of the Higgs, along with advanced data analysis techniques such as machine learning and anomaly detection, for broad and unprecedented sensitivity. The High Luminosity LHC, the corresponding ATLAS detector upgrade, and studies for future experiments are all crucial for the longevity of these searches. These topics are discussed in the context of cross-field collaboration and long-term strategic planning for the continued success of the field, ensuring that no stone is left unturned in the effort to understand fundamental particle physics.",https://events.umich.edu/event/102429,"West Hall",340,"West Hall",,"colloquium
Complex Systems
Faculty
Natural Sciences
seminar","Department Colloquia
Department of Physics"
102481-21804111,"2023-01-13 10:00:00","2023-01-13 11:00:00","Statistics Department Seminar Series: Blair Bilodeau, PhD candidate, Department of Statistical Sciences, University of Toronto","""Adaptive Sequential Decision Making and Uncertainty Quantification""","Workshop / Seminar","Abstract: One way to quantify the risks of deploying complex statistical methods is theoretical guarantees, yet statistical theory often relies on unverifiable assumptions and can therefore fail to explain performance in real-world settings. My research seeks out guarantees without such limitations across a wide range of statistical tasks, including inference, prediction, and decision making. In this talk, I will present two papers from this research program.
First, I will present https://arxiv.org/abs/2202.05100 (awarded an Oral designation at NeurIPS 2022, reserved for only 2% of submissions), where we study how to most efficiently select interventions in sequence to learn causal effects. We provide an adaptive method and corresponding guarantees: simultaneously optimal performance when benign causal structure exists and consistent estimation even when all causal assumptions fail. Second, I will present https://arxiv.org/abs/2109.10461, where we resolve the minimax rates for conditional density estimation in parametric and nonparametric classes. I will particularly focus on consequences of our results, including the first dimension-free KL risk bounds for generalized linear models, the first fast rates for KL risk with arbitrarily unbounded covariate spaces, and the first characterizations of KL risk for natural extensions of smoothness to conditional densities. Finally, I will discuss how these advances form a foundation of my future research: general adaptivity in non-stationary and partial-feedback settings.
Bio: Blair Bilodeau is a graduating PhD student in Statistical Sciences at the University of Toronto, advised by Daniel Roy. His PhD was funded by an NSERC Canada Graduate Scholarship and the Vector Institute. Blair’s work has been internationally recognized, including a Rising Star in Data Science award from the University of Chicago, an IMS Hannan Graduate Student Award, and a New York Academy of Science Best Poster Award. Open access versions of his publications and his full CV are available at http://www.blairbilodeau.ca.",https://events.umich.edu/event/102481,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
103056-21805783,"2023-01-17 15:00:00","2023-01-17 16:00:00","CM-AMO Seminar | Seeing Life in a New Light: From Simple Classical Physics to Quantum-Enhanced Imaging","Vladislav Yakovlev (Texas A&M University)","Workshop / Seminar","The progress of biomedical sciences depends on the availability of advanced instrumentation and imaging tools capable of attaining the state of biological systems in vivo without using exogenous markers. Mechanical forces and local elasticity play a central role in understanding physical interactions in all living systems. We demonstrate a novel way to image microscopic viscoelastic properties of biological systems using Brillouin microspectroscopy [1]. In my talk, I will discuss the ways how an old spectroscopic tool can be used for real time microscopy and provide possible solutions to long standing problems in Life Sciences and Medicine while advancing instrumentation beyond classical limits [2].
[1] Zh. Meng, A. Traverso, C. Ballmann, M. Troyanova-Wood, and V. V. Yakovlev, “Seeing cells in a new light: a renaissance of Brillouin spectroscopy,” Advances in Optics and Photonics 8(2), 300-327 (2016).
[2] T. Li, F. Li, X. Liu, V. V. Yakovlev, and G. S. Agarwal, “Quantum-Enhanced Continuous-Wave Stimulated Brillouin Scattering Spectroscopy and Imaging,” Optica 9(8), 959-964 (2022).",https://events.umich.edu/event/103056,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
102483-21804112,"2023-01-17 16:00:00","2023-01-17 17:00:00","Statistics Department Seminar Series: Wenlong Mou PhD Candidate, Department of EECS, University of California, Berkeley",""" Instance-dependent optimality in statistical decision-making: what they mean and how to achieve them?""","Workshop / Seminar","Abstract: Data-driven methodology is a pillar of real-world decision-making. When applying statistical learning methods, puzzling phenomena have arisen in choosing estimators, tuning their parameters, and characterizing bias-variance trade-offs. There are various settings in which asymptotic and/or worst-case theory fails to provide the relevant guidance, so that a more refined approach, both non-asymptotic and instance-optimal, is required.
In this talk, I present some recent advances in optimal procedures for statistical decision-making. I will first discuss function approximation methods for policy evaluation in reinforcement learning. I describe a novel class of optimal and instance-dependent oracle inequalities for projected Bellman equations. Different from statistical learning, the optimal approximation factor depends on the geometry of the problem, and can be much larger than unity. Drawing on this perspective, I then discuss instance-dependent optimal methods for estimating linear functionals from observational data. With a practical sample size, the optimal risks exhibit a rich spectrum of behavior beyond the asymptotic semi-parametric efficiency bound. Our non-asymptotic instance-dependent results identify the fundamental roles of certain novel quantities, and provide concrete guidance on practical choices.
Bio: Wenlong Mou is a Ph.D. student at Department of EECS, UC Berkeley, advised by Martin Wainwright and Peter Bartlett. Prior to Berkeley, he received his B.Sc. degree in Computer Science from Peking University. Wenlong's research interests include statistics, machine learning theory, dynamic programming and optimization, and applied probability. He is particularly interested in designing optimal statistical methods that enable optimal data-driven decision making, powered by efficient computational algorithms.
https://people.eecs.berkeley.edu/~wmou/",https://events.umich.edu/event/102483,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
103221-21806365,"2023-01-18 15:00:00","2023-01-18 16:00:00","MLK Department Colloquium | M.L.King Jr., Albert Einstein, and YOU 2","Willie S. Rockward (Morgan State University)","Workshop / Seminar","This colloquium/talk will address the concepts, connections, and conclusions of these 2 great personalities -- Martin Luther King, Jr. and Albert Einstein and how it applies to the physics community through the lens of diversity, equity, and inclusiveness.
https://www.symmetrymagazine.org/article/changing-the-game
BIOGRAPHY
WILLIE S. ROCKWARD, Ph.D.
Chair and Professor of Physics
Department of Physics & Engineering Physics
Morgan State University, Baltimore, MD
Education:
Ph.D. Physics, Georgia Institute of Technology
M.S. Physics, Georgia Institute of Technology
M.S. Physics, State University of New York, Albany
B.S. Physics, Grambling State University
Dr. Rockward has a unique combination of leadership from academic, professional, and community experiences. Since August 2018, he serves as the Chair of the Department of Physics & Engineering Physics at Morgan State University, Baltimore, Maryland. Prior to his transition to Morgan State, he served 7 years as the Chair of the Department of Physics & Dual Degree Engineering Program (Physics & DDEP) and 20 years as the Research Director of the Materials and Optics Research & Engineering (MORE) Laboratory at Morehouse College, Atlanta, Georgia. Among his professional leadership experiences, he is the immediate Past President of both the National Society of Black Physicists (NSBP) and the Sigma Pi Sigma Physics Honor Society. Also, he has served a combination of 30+ years as (1) Senior Pastor of the Divine Unity Missionary Baptist Church, East Point, Georgia; (2) Associate Minister of Antioch Baptist Church North, Atlanta, Georgia; and (3) Associate Minister of New Shiloh Baptist Church, Baltimore, Maryland.
As Chair of Physics & DDEP at Morehouse College, his vision and leadership resulted in 7 consecutive years of the department being the US #1 producer for underrepresented minorities with Bachelor of Science degrees in Physics according to the American Institute of Physics in conjunction to boasting the Nation’s most productive Dual Degree Engineering Program. He is a strong proponent of STEM mentorship using methodologies of faculty-to-student, peer-to-peer, professional shadowing, life-skills coaching, and research apprenticeship. His current research interests include micro/nanolithography, extreme ultraviolet interferometry, metamaterials, terahertz imaging, nanostructure characterization, and crossed phase optics.",https://events.umich.edu/event/103221,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
102484-21804114,"2023-01-20 10:00:00","2023-01-20 11:00:00","Statistics Department Seminar Series: Gemma Moran, Postdoctoral Research Fellow, Data Science Institute, Columbia University","""Identifiable Deep Generative Models via Sparse Decoding""","Workshop / Seminar","Abstract: We develop the sparse VAE for unsupervised representation learning on high-dimensional data. The sparse VAE learns a set of latent factors (representations) which summarize the associations in the observed data features. The underlying model is sparse in that each observed feature (i.e. each dimension of the data) depends on a small subset of the latent factors. As examples, in ratings data each movie is only described by a few genres; in text data each word is only applicable to a few topics; in genomics, each gene is active in only a few biological processes. We prove such sparse deep generative models are identifiable: with infinite data, the true model parameters can be learned. (In contrast, most deep generative models are not identifiable.) We empirically study the sparse VAE with both simulated and real data. We find that it recovers meaningful latent factors and has smaller heldout reconstruction error than related methods.
https://www.gemma-moran.com/",https://events.umich.edu/event/102484,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
103147-21806181,"2023-01-20 12:00:00","2023-01-20 13:00:00","LAGS Seminar | How To Do Great Things","Adam Sypniewski (CTO at Deepgram)","Workshop / Seminar","Join Zoom Meeting
https://umich.zoom.us/j/95573161835
Meeting ID: 955 7316 1835
Passcode: 054136
What makes for a great idea? What kinds of ideas drive true technological revolution? In this talk, we will explore characteristics of great ideas and how to convert those ideas into successful startups. With an eye towards artificial intelligence, we will discuss coming up with great ideas, building out those ideas, and hiring great teams to execute on those ideas.",https://events.umich.edu/event/103147,"West Hall",335,"West Hall",,"Physics
Science","Life After Grad School Seminars
Department of Physics"
102651-21804904,"2023-01-23 10:00:00","2023-01-23 11:00:00","Special Physics Department Seminar | Thin Sheets as Condensed Matter","Suraj Shankar, Postdoctoral Fellow (Harvard University)","Workshop / Seminar","Join on Zoom: https://umich.zoom.us/j/95091149061
Thin elastic sheets display a stunning array of complex morphologies, instabilities and dynamics across scales, from crumpled paper and ruffled leaves to atomically thin graphene. Like in traditional condensed matter, such ""collective"" phenomena often emerge on large scales, only now through an interplay of geometry and mechanics rather than microscopic material properties.
In this talk, I will show how a geometric focus allows thin sheets to be fruitfully viewed as condensed matter, exhibiting simple analogies with electrostatics and phase transitions to more exotic ones like topological insulators. I will highlight the benefit and consequences of this approach to recent efforts in mechanical metrology and the design of ultrathin nanodevices and mechanical metamaterials.",https://events.umich.edu/event/102651,"West Hall",340,"West Hall",,"colloquium
Complex Systems
Faculty
Natural Sciences
seminar","Department Colloquia
Department of Physics"
103034-21805743,"2023-01-23 15:00:00","2023-01-23 16:00:00","HEP-Astro Seminar | High Energy Astrophysics with IceCube: Evidence for Neutrino Emission From the Nearby Active Galaxy NGC 1068","Hans Niederhausen (Michigan State University)","Workshop / Seminar","The IceCube Neutrino Observatory, deployed beneath the South Pole, is the largest optical neutrino telescope in the World. IceCube has been measuring a diffuse flux of high-energy (TeV and above) astrophysical neutrinos for almost a decade. The sources of the vast majority of these neutrinos remain elusive, but studies indicate that gamma-ray obscured sources may at least in parts be responsible. Most recently, IceCube reported strong evidence for TeV neutrino emission from NGC 1068, a well-known and nearby active galaxy. I will explain how IceCube searches for neutrinos from astrophysical sources and how recent improvements in our analysis methods enabled this result. When put into the multi-messenger context, in particular the non-detection of TeV gamma-rays by the MAGIC telescopes, this measurement suggests that the gamma-ray obscured vicinity of the central supermassive black hole acts as a cosmic hadron accelerator. The next steps are clear. By studying similar objects we may finally identify a class of sources that makes a sizeable contribution to the diffuse flux of astrophysical neutrinos.",https://events.umich.edu/event/103034,"West Hall",335,"West Hall",,"Astronomy
Physics
Science","Department of Physics
HEP - Astro Seminars"
102487-21804126,"2023-01-24 16:00:00","2023-01-24 17:00:00","Statistics Department Seminar Series: Richard Guo Research Associate, Statistical Laboratory, University of Cambridge","""Harnessing Extra Randomness: Replicability, Flexibility and Causality""","Workshop / Seminar","Abstract: Many modern statistical procedures are randomized in the sense that the output is a random function of data. For example, many procedures employ data splitting, which randomly divides the dataset into disjoint parts for separate purposes. Despite their flexibility and popularity, data splitting and other constructions of randomized procedures have obvious drawbacks. First, two analyses of the same dataset may lead to different results due to the extra randomness introduced. Second, randomized procedures typically lose statistical power because the entire sample is not fully utilized.
To address these drawbacks, in this talk, I will study how to properly combine the results from multiple realizations (such as through multiple data splits) of a randomized procedure. I will introduce rank-transformed subsampling as a general method for delivering large sample inference of the combined result under minimal assumptions. I will illustrate the method with three applications: (1) a “hunt-and-test” procedure for detecting cancer subtypes using high-dimensional gene expression data, (2) testing the hypothesis of no direct effect in a sequentially randomized trial and (3) calibrating cross-fit “double machine learning” confidence intervals. For these problems, our method is able to de-randomize and improve power or coverage. Moreover, in contrast to existing approaches for combining p-values, our method enjoys type-I error control that asymptotically approaches the nominal level. This new development opens up the possibility of designing procedures that explicitly randomize and de-randomize: extra randomness is introduced to make the problem easier before being removed.
This talk is based on joint work with Rajen Shah.
Bio: Richard Guo is a research associate in the Statistical Laboratory at the University of Cambridge, mentored by Rajen Shah. In Spring 2022, he was the Richard M. Karp Research Fellow in the causality program at the Simons Institute for the Theory of Computing. He received his PhD in Statistics from University of Washington in 2021, advised by Thomas Richardson, for which he received the Z. W. Birnbaum Award. His research interests include graphical models, causal inference and replicability of data analysis.
https://unbiased.co.in/",https://events.umich.edu/event/102487,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
103130-21806155,"2023-01-25 15:00:00","2023-01-25 16:00:00","Department Colloquium | Vegetation Pattern Formation in Drylands","Mary Silber (University of Chicago)","Workshop / Seminar","A beautiful example of spontaneous pattern formation occurs in certain dryland environments around the globe, where stripes of vegetation alternate with stripes of bare soil, with striking regularity and on a scale readily monitored by remote-sensing satellites. Theoretical ecologists, together with theoretical physicists and applied mathematicians, have also exploited the physicist's understanding of mechanisms of spontaneous self-organization to model these dryland vegetation patterns. They have shown how these spatial patterns exploit positive feedbacks to efficiently concentrate the limited water resource into vegetated zones. This talk will present a few research vignettes on this topic of vegetation pattern formation in dryland ecosystems. It is research that is motivated by the vulnerability of these fragile ecosystems to increased desertification under climate change and changes in human land-use.",https://events.umich.edu/event/103130,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
102490-21804128,"2023-01-27 10:00:00","2023-01-27 11:00:00","Statistics Department Seminar Series: Zhimei Ren, Postdoctoral Research Fellow, Department of Statistics, University of Chicago","""Stable Variable Selection with Knockoffs""","Workshop / Seminar","Abstract: A common problem in many modern statistical applications is to find a set of important variables—from a pool of many candidates—that explain the response of interest. For this task, model-X knockoffs offers a general framework that can leverage any feature importance measure to produce a variable selection algorithm: it discovers true effects while rigorously controlling the number or fraction of false positives, paving the way for reproducible scientific discoveries. The model-X knockoffs, however, is a randomized procedure that relies on the one-time construction of synthetic (random) variables. Different runs of model-X knockoffs on the same dataset often result in different sets of selected variables, which is not desirable for the reproducibility of the reported results.
In this talk, I will introduce derandomization schemes that aggregate the selection results across multiple runs of the knockoffs algorithm to yield stable selection. In the first part, I will present a derandomization scheme that controls the number of false positives, i.e., the per family error rate (PFER) and the k family-wise error rate (k-FWER). In the second part, I will talk about an alternative derandomization scheme with provable false discovery rate (FDR) control. Equipped with these derandomization steps, the knockoffs framework provides a powerful tool for making reproducible scientific discoveries. The proposed methods are evaluated on both simulated and real data, demonstrating comparable power and dramatically lower selection variability when compared with the original model-X knockoffs.
https://zhimeir.github.io/",https://events.umich.edu/event/102490,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
103457-21807230,"2023-01-27 15:00:00","2023-01-27 16:00:00","HET Seminar | Complexity=Anything","Rob Myers (Perimeter)","Lecture / Discussion","Motivated by holographic complexity, we examine a new class of gravitational observables in asymptotically AdS space associated with codimension-one slices or with codimension-zero regions. We argue that any of these observables is an equally viable candidate as the extremal volume for a gravitational dual of complexity.",https://events.umich.edu/event/103457,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics
Science","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
103136-21806163,"2023-01-30 15:00:00","2023-01-30 16:00:00","HEP-Astro Seminar | 3D Position-Sensitive CdZnTe Gamma-Ray Imaging Spectrometers and Their Applications","Zhong He (U-M Engineering)","Workshop / Seminar","This presentation highlights the latest technology advancement on 3-dimensional position-sensitive room-temperature CdZnTe (CZT) semiconductor gamma-ray imaging spectrometers. Sustained advancement on CZT detector technology, including larger detection volume, digital application specific integrated circuit (H3DD-UM ASIC) and integrated electronic data acquisition systems will be described, as well as research and development on alternative semiconductor gamma-ray spectrometers. The applications of 3D CZT detectors will be summarized in national security, nuclear power industry, international nuclear safeguard and non-proliferation, space exploration, and medical imaging. The operational principle and unique capabilities will be introduced to explore potential applications in fundamental physics and astrophysics.",https://events.umich.edu/event/103136,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
103829-21807977,"2023-01-31 15:00:00","2023-01-31 16:00:00","CM-AMO Seminar | Double Feature","Yang Yu (U-M Physics) and Torben Purz (MONSTR Sense Technologies)","Workshop / Seminar","Yang Yu
U-M Physics
Magnetic Phases of the Anisotropic Triangular Lattice Hubbard Model
The Hubbard model on an anisotropic triangular lattice in two dimensions, a fundamental model for frustrated electron physics, displays a wide variety of phases and phase transitions. This work investigates the model using the ladder dual fermion approximation which captures local correlations non-perturbatively but approximates non-local correlations. We find metallic, one-dimensional antiferromagnetic, non-collinear antiferromagnetic, square-lattice antiferromagnetic, and spiral phases but no evidence of collinear antiferromagnetic order in different parts of the phase diagram. Analyzing the spin susceptibility in detail, we see both regions of agreement and of discrepancy with previous work. The case of Cs2CuCl4 is discussed in detail.
Reference:
https://arxiv.org/abs/2211.09234.
Torben Purz
MONSTR Sense Technologies
Coherent Imaging Spectroscopy of Transition Metal Dichalcogenides
Transition Metal Dichalcogenides (TMDs) monolayers and heterostructures are a promising material platform for quantum information science, photovoltaics, and related device applications. In the past decade, much effort has been dedicated to explore the exciton physics in these materials, ranging from their strong light-matter coupling to charge transfer and coherent coupling. However, many demonstrations in TMDs can only be realized at specific spots on the sample, presenting a challenge to the scalability of these applications.
In this talk, I will demonstrate Multi-Dimensional Coherent Imaging Spectroscopy of TMDs and highlight the sensitivity of exciton spatial and temporal coherence toward strain while coherent exciton coupling and charge transfer in these samples remain mostly unaffected, strengthening the case for TMDs as next-generation material platform in quantum information science and beyond. In addition, I will demonstrate rapid nonlinear imaging spectroscopy of TMDs that assesses the quality of samples through measurement of their nonlinear response, exciton dephasing, exciton lifetimes, and exciton-coupling strength. By comparison, I will show that extracting material parameters such as four-wave mixing intensity, dephasing times, excited state lifetimes, exciton-coupling strength, and distribution of dark/localized states allows for a more accurate assessment of the quality of a sample than current prevalent techniques, including white light microscopy, linear micro-reflectance spectroscopy, and photo-luminescence.",https://events.umich.edu/event/103829,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
102491-21804129,"2023-01-31 16:00:00","2023-01-31 17:00:00","Statistics Department Seminar Series: Kevin Lin, Postdoctoral Research Fellow, Department of Statistics and Data Science, Wharton School, University of Pennsylvania","""Tilted-CCA: Quantifying common and distinct information in multi-modal single-cell data via matrix factorization""","Workshop / Seminar","Abstract: Recently, multi-modal single-cell data has been growing in popularity in many areas of biomedical research and provides new opportunities to learn how different modalities coordinate within each cell. Many existing dimension reduction methods for such data estimate a low-dimensional embedding that captures all the axes of variation from either modality. While these current methods are useful, we develop the Tilted-CCA in this talk to perform a fundamentally different task. This method is a novel matrix factorization that estimates low-dimensional embeddings separating the axes of variation shared between both modalities (i.e., ""common geometry,"" capturing the coordination between both modalities) from axes of variation unique to a particular modality (i.e., ""distinct geometry""). Methodologically, Tilted-CCA achieves this by combining ideas from Canonical Correlation Analysis (CCA) and density clustering. Our method first uses the nearest-neighbor graphs from each modality to infer the common geometry between both modalities and decomposes the canonical scores from CCA to approximate this geometry. Biologically, Tilted-CCA unveils the cellular dynamics in developmental systems based on the proportion of variation between the common and distinct embeddings. More broadly, Tilted-CCA invites new theoretical questions regarding dimension reduction and can be applied to any domain beyond single-cell genomics.
Short biography:
Kevin Lin is a current post-doctoral researcher at the University of Pennsylvania's Wharton Department of Statistics & Data Science with Dr. Nancy Zhang and completed his Ph.D. at Carnegie Mellon University's Department of Statistics & Data Science under Dr. Kathryn Roeder and Dr. Jing Lei. His research focuses on studying cellular mechanisms from single-cell data. He develops novel methods using ideas from matrix factorization, network modeling, and changepoint detection to derive new theoretical and biological insights, and he collaborates with both statisticians and biologists.",https://events.umich.edu/event/102491,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
103589-21807522,"2023-01-31 17:00:00","2023-01-31 18:00:00","Snack Time!",,"Workshop / Seminar","Instead of a talk today, we'll be having snack time! Join us at 5 pm to chat and have some food.",https://events.umich.edu/event/103589,"West Hall",335,"West Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics"
103349-21807069,"2023-02-01 15:00:00","2023-02-01 16:00:00","Department Colloquium | SPARC and the High-field Path to Fusion Energy","Dennis Whyte (MIT)","Workshop / Seminar","The advent of REBCO high-temperature superconductors at commercial scale has changed the development path for producing fusion energy with magnetic confinement.
The design and test of a large-bore B>20 tesla peak field superconducting magnet at MIT PSFC, in collaboration with Commonwealth Fusion Systems, realizes a doubling of the allowed B field compared to previous state of the art. This realizes extremely large gains in fusion performance fusion power density scales as B^4 and access to ignition as ~B^5 at fixed plasma physics.
These gains in turn allow for operation away from limits, yet in much smaller and less expensive devices. CFS is presently constructing the high-B tokamak SPARC outside Boston with MIT as its major scientific collaborator, with the goal of demonstrating high fusion energy gain and fusion power density that propels fusion into the commercial energy sector. In addition to describing SPARC, parallel key fusion technology development programs in will be described.",https://events.umich.edu/event/103349,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
104211-21808649,"2023-02-06 15:00:00","2023-02-06 16:00:00","HEP-Astro Seminar | Directly Detecting Light Dark Matter","Robert McGehee (U-M Physics)","Workshop / Seminar","While the experimental program to detect ever lighter dark matter is proceeding full steam ahead, the theory of such light, detectable dark matter is at a crossroads. I will detail two examples of sub-GeV hadrophilic dark matter models which these future direct detection endeavors may discover while highlighting the serious challenges model builders face. The first achieves probe-able direct detection cross sections by way of a late-time, dark-sector phase transition, while the second does so by assuming the entire thermal bath is reheated at very low temperatures. Both models lead to dark matter-nucleon scattering cross sections of interest for near-future experiments for dark matter masses in the range of 100 keV-100 MeV, often in parts of parameter space with few or no models.",https://events.umich.edu/event/104211,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
103124-21806149,"2023-02-07 15:00:00","2023-02-07 16:00:00","CM-AMO Seminar | Charge Density Wave and Spin Nematic Phase in Kagome Lattice FeGe","Pengcheng Dai (Rice University)","Workshop / Seminar","Join Zoom Meeting
https://umich.zoom.us/j/91632009290
Meeting ID: 916 3200 9290
Passcode: 595628
A hallmark of strongly correlated quantum materials is the rich phase diagram resulting from competing and intertwined phases with nearly degenerate ground state energies. A well-known example is the copper oxides, where a charge density wave (CDW) is ordered well above and strongly coupled to the magnetic order to form spin-charge separated stripes that compete with superconductivity. Recently, such rich phase diagrams have also been revealed in correlated topological materials. In two-dimensional kagome lattice metals consisting of corner-sharing triangles, the geometry of the lattice can produce flat bands with localized electrons, non-trivial topology, chiral magnetic order, superconductivity and CDW order. While CDW has been found in weakly electron correlated nonmagnetic AV_3Sb_5 (A = K, Rb, Cs), it has not yet been observed in correlated magnetic ordered kagome lattice metals. Here we report the discovery of CDW within the antiferromagnetic (AFM) ordered phase of kagome lattice FeGe. The CDW in FeGe occurs at wavevectors identical to that of AV_3Sb_5, enhances the AFM ordered moment, and induces an emergent anomalous Hall effect. Our findings suggest that CDW in FeGe arises from the combination of electron correlations-driven AFM order and van Hove singularities-driven instability possibly associated with a chiral flux phase, in stark contrast to strongly correlated copper oxides and nickelates, where the CDW precedes or accompanies the magnetic order. We will also discuss our recent discovery of a spin nematic phase in FeGe.",https://events.umich.edu/event/103124,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
103833-21807980,"2023-02-08 15:00:00","2023-02-08 16:00:00","2023 Helmut W. Baer Lecture | The Insidious Neutrinos, Entropy, and Gravitational Collapse","George M. Fuller, Distinguished Professor of Physics (University of California, San Diego)","Workshop / Seminar","This will be a hybrid event. Livestream Link: https://www.youtube.com/watch?v=lufAjs_V5Ys
The Insidious Neutrinos, Entropy, and Gravitational Collapse: what we learn about neutrinos, beyond standard model physics, and the creation of the elements, from the collapse of massive stars
The weakest forces of nature team up to engineer the demise of massive stars, compact objects, and maybe the odd causal horizon volume in the very early universe.
Stars make a Faustian bargain with gravitation and the weak interaction: Energy generation and, hence, promise of a longer life, in exchange for changing composition and the seemingly innocent loss of a little entropy through neutrino emission. It is a good deal for lower-mass stars like the sun. But the price proves to be too high for stars with masses in excess of ~ 8 solar masses, where the neutrino emission-induced loss of entropy and the nonlinear nature of gravitation combine with the weak interaction and exotic nuclear physics to cause collapse of the cores of these stars to neutron stars or black holes. Stars with masses in excess of ~ 100 solar masses likewise are vulnerable to instability because so much of their pressure support comes from radiation.
In fact, the nonlinear nature of gravitation means that self-gravitating systems get into trouble whenever their pressure support involves particles moving near light speed. Such objects are, in the words of my late research mentor, “Trembling on the verge of instability.”
That means that very subtle influences, from known, standard model weak interaction processes, but perhaps also from new, beyond-standard-model physics, can figure in the evolution of these objects. Collapse to neutron stars or black holes is the inevitable outcome, but clues about how these murders were committed may be found in nucleosynthesis (especially of the heaviest nuclei) and in the spectrum of remnant masses.
We will discuss how frontier issues in elementary particle physics, especially those involving the mysterious and ghostlike neutrinos, could figure prominently in what happens in these gravitational collapse events and their aftermath.",https://events.umich.edu/event/103833,"West Hall",340,"West Hall",,"AEM Featured
Physics","Department Colloquia
Department of Astronomy
Department of Physics
The Center for the Study of Complex Systems
Applied Physics
LSA Biophysics
Department of Mathematics
Astronomy Colloquia
Undergrad Physics Events"
104022-21808284,"2023-02-10 10:00:00","2023-02-10 11:00:00","Statistics Department Seminar Series: James Zou, Assistant Professor of Biomedical Data Science, Computer Science, and Electrical Engineering, Stanford University","""Clinical trials for AI and AI for clinical trials""","Workshop / Seminar","Abstract: Clinical trials are the gatekeeper and bottleneck of medicine. In the first half of the talk, I discuss lessons learned from our systematic analysis of all the FDA-approved medical AI devices, which reveals key limitations in how AIs are evaluated (Wu et al. Nature Medicine 2021). Motivated by this, I share the design and results from our recent randomized prospective clinical trial evaluating EchoNet, a computer vision AI for assessing cardiac conditions. In the second half, I will discuss how to use AI (Trial Pathfinder) to make clinical trials more diverse and efficient (Liu et al. Nature 2021, Nature Medicine 2022). Trial Pathfinder is used by pharma companies to guide new trials and was selected as a Top Ten Clinical Research Achievement.
Bio: James Zou is an assistant professor of Biomedical Data Science, CS and EE at Stanford University. He develops machine learning methods for biology and medicine. He works on both improving the foundations of ML–-by making models more trustworthy and reliable–-as well as in-depth scientific and clinical applications. He has received a Sloan Fellowship, an NSF CAREER Award, two Chan-Zuckerberg Investigator Awards, a Top Ten Clinical Achievement Award, several best paper awards, and faculty awards from Google, Amazon, Tencent and Adobe.
https://www.james-zou.com/",https://events.umich.edu/event/104022,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
103125-21806150,"2023-02-14 15:00:00","2023-02-14 16:00:00","CM-AMO Seminar | 2-D Terahertz Spectroscopy of Cuprate Superconductors","Albert Liu (Max Planck Institute)","Workshop / Seminar","Quantum materials, systems in which quantum effects lead to unique macroscopic phenomena with tremendous technological potential, comprise the forefront of condensed matter physics research. In particular, collective excitations associated with broken-symmetry phases have attracted tremendous attention as powerful windows into their microscopic physics and dynamics. However, spectroscopy of these collective excitations has been hindered by the so-called ‘terahertz gap’, which refers to difficulties in generation and detection of radiation in the terahertz frequency range, where many relevant modes of quantum materials are found.
In response to this challenge, we translate a technique known as 2-D spectroscopy, an optical analogue of multi-dimensional NMR spectroscopy, into the terahertz frequency range. We implement, for the first time, 2-D Terahertz Spectroscopy in a non-collinear, reflection geometry, enabling study of opaque materials and isolation of their constituent terahertz nonlinearities. We apply this technique to the Josephson plasma resonance in La2-xSrxCuO4, a layered high-temperature superconductor, to distill the underlying plasmon correlations. Measurements of the superconducting transition provide evidence of an unconventional phase-disordering transition without pair breaking. I will conclude with an outlook for applying 2-D Terahertz Spectroscopy towards studying light-induced phase transitions.",https://events.umich.edu/event/103125,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
104867-21810376,"2023-02-14 17:00:00","2023-02-14 18:00:00","Rank-one perturbation of large random matrices","Han Le","Workshop / Seminar","In this talk, we consider Wigner matrices that have been deformed by the addition of a rank-one matrix belonging to the same symmetry class. In particular, we will discuss how the deformation affects the global eigenvalue statistics as well as the behavior of individual eigenvalues. We then examine different phases that the free energy of the spherical SK model exhibits when the random matrix encoding interactions between spins is additively perturbed as above.",https://events.umich.edu/event/104867,"West Hall",335,"West Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics"
104035-21808300,"2023-02-15 15:00:00","2023-02-15 16:00:00","Department Colloquium | The Sound of Quantum Mechanics","Konrad Lehnert (JILA)","Workshop / Seminar","In the past decade a new technology domain of quantum sound has emerged. Unlike electrical and optical systems, which are governed by fundamental equations of electromagnetism, acoustical and vibrational phenomena are described by the equations of elastic waves in solid bodies. They are subject to different limitations and can reach different regimes of behavior. Sound is different. The speed of sound in a solid material is 100,000-fold slower than light, elastic waves do not propagate through vacuum, and they can couple to atom-like systems through strain rather than electrical or magnetic dipole interactions. These facts have consequences for quantum information science that we have yet to fully understand. In his talk, I will describe the emergence of this new branch of quantum science, showing both striking demonstrations of quantum sound and highlighting potential applications. In particular, I will demonstrate the dual wave-particle nature of phonons and discuss how quantum acoustics might be the key enabling technology for quantum communication networks.",https://events.umich.edu/event/104035,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
104302-21808807,"2023-02-17 10:00:00","2023-02-17 11:00:00","Statistics Department Seminar Series: Richard Zemel, Professor, Department of Computer Science, Columbia University","""Quantile Risk Control: A Framework for Flexible Bounds on the Probability of High-Loss Predictions""","Workshop / Seminar","Abstract: Learning-based predictive algorithms have tremendous potential to reduce costs and improve outcomes in a breadth of domains including business, healthcare, and government. Rigorous guarantees about the performance of such powerful algorithms are necessary in order to ensure their responsible use. I will describe current results in this area, focusing on the most recent work, which bounds the expected loss of a predictor. In many risk-sensitive applications this is not sufficient, as the distribution of errors is important. In such cases, the quantiles of the loss distribution incurred by a predictor are an alternative and informative way of quantifying its performance. I will present a new framework we have developed for deriving a variety of efficient upper bounds on loss quantiles, which
encompasses previous methods and offers novel formulations. The quantiles can be used as the basis for model validation to select the best predictor from a set, and issue rigorous guarantees on its generalization performance. I will present theoretical properties of our proposed method and demonstrate its ability to control loss quantiles on several real-world datasets.
https://www.cs.columbia.edu/~zemel/",https://events.umich.edu/event/104302,"West Hall",340,"West Hall",,Physics,"Department of Statistics
Department of Statistics Seminar Series"
104723-21809959,"2023-02-17 15:00:00","2023-02-17 16:00:00","HET Seminar | Information loss, Chaos, and the Emergence of Type III1 Algebras","Nima Lashkari (Purdue)","Lecture / Discussion","The decay of the left-right correlators in an eternal black hole is one of the simplest manifestations of the black hole information loss problem.
The subalgebras of left and right decorrelate under the time evolution asymptotically, and monotonically due to the stretching of the wormhole.
From the point of view of quantum mechanics, dynamical decorrelation is so special that can be used as a clue to the nature of operator algebras in quantum gravity.
In particular, I will argue that asymptotic decorrelation uniquely fixes the operator algebras to be the type III1 von Neumann algebras. I will comment on the connections between the emergence of the second law, the decay of the out-of-time-ordered correlator (chaos), and the emergence of type III1 algebras.",https://events.umich.edu/event/104723,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics
Science","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
104070-21808362,"2023-02-17 15:00:00","2023-02-17 16:30:00","The Michigan Anthropology Colloquia Series","""The Petro-State Masquerade"" by Ryan Cecil Jobson","Lecture / Discussion","The Department of Anthropology proudly presents
Michigan Anthropology Colloquia Series
""The Petro-State Masquerade:
Oil and Sovereignty in Trinidad and Tobago""
By Ryan Cecil Jobson
Neubauer Family Assistant Professor of Anthropology
University of Chicago
In-person and virtual
3:00 - 4:30 PM
West Hall, Room 411
https://umich.zoom.us/j/92496167134
“The Petro-State Masquerade” considers how postcolonial political futures in the Caribbean nation-state of Trinidad and Tobago came to be staked to the market futures of oil, natural gas, and their petrochemical derivatives.
Drawing on archival and ethnographic research, Jobson theorizes how the tenuous relationship between oil and political power—enshrined in the hyphenated form of the petro-state—is represented by postcolonial state officials as a Carnivalesque “masquerade of permanence” through the perpetual expansion of fossil fuel ventures. At the same time, low oil and gas prices, diminishing reserves, and renewable energy innovations threaten the viability of the Trinbagonian energy sector. In turn, Jobson examines the turn to offshore exploration in the deepwater sector beginning in 1998.
Characterized by protracted production cycles, deepwater ventures feature prohibitive costs and a comparatively low probability of success. After several deepwater ventures failed to yield substantive commercial quantities of oil or gas, the unfulfilled potential of a lucrative offshore geology is invoked to mitigate uncertainty and secure the long-term viability of the Trinbagonian energy sector. In their masquerade, state officials depict fossil fuels as inexhaustible resources waiting to be unearthed by multinational capital and novel extractive technologies.",https://events.umich.edu/event/104070,"West Hall",411,"West Hall",,"AEM Featured
Anthropology
Free","Department of Anthropology"
105149-21811183,"2023-02-21 17:00:00","2023-02-21 18:00:00","Semi-global existence theory for wave equations","Christopher Stith","Workshop / Seminar","Bootstrap methods are a powerful tool for proving quantitative existence results in the theory of partial differential equations. We will discuss these in the context of nonlinear wave equations and discuss applications to general relativity. Along the way we will construct various energies that arise in the study of such equations and discuss how these are used in their analysis.",https://events.umich.edu/event/105149,"West Hall",335,"West Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics"
104945-21810493,"2023-02-22 15:00:00","2023-02-22 16:00:00","Department Colloquium | Applying the Materials Physics Paradigm to Biology","Aparna Baskaran (Brandeis University)","Workshop / Seminar","Active matter is a term that has come to describe diverse systems from flocking animals to the cytoskeleton of a cell. In this talk I will give an overview of the theoretical paradigm that unifies these diverse systems and discuss some results from minimal models for self-propelled particles and suspension of cytoskeletal filaments. Then, I will present recent theoretical progress in using data driven techniques to bridge experiment and theory in active suspensions.",https://events.umich.edu/event/104945,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
104311-21808812,"2023-02-24 10:00:00","2023-02-24 11:00:00","Statistics Department Seminar Series: Luay Nakhleh, Dean of the George R. Brown School of Engineering, Rice University","""Phylogenomic Inference of Reticulate Evolutionary Histories""","Workshop / Seminar","ABSTRACT: Using genome-wide data for phylogenetic inference and analysis has become commonplace in the post-genomic era, giving rise to the field of phylogenomics. The multispecies coalescent (MSC) model has emerged as the main stochastic process that helps capture the intricate relationship between species trees and gene trees. Combined with models of sequence evolution, the MSC can be viewed as a generative model of genomic sequence data in the context of a (species) phylogenetic tree. A significant outcome of the use of genome-wide data has been the increasing evidence, or hypotheses, of reticulation (e.g., hybridization) during the evolution of various groups of eukaryotic species. Reticulate evolutionary histories are best represented as phylogenetic networks, which extend the tree model to allow for admixtures of genetic material. In this talk, I will describe the multispecies network coalescent (MSNC) model, which extends the MSC model so that it operates within the branches of a phylogenetic network. This extended model naturally allows for modeling vertical and horizontal evolutionary processes acting within and across species boundaries. In particular, it simultaneously accounts for gene tree incongruence across loci due to both hybridization and incomplete lineage sorting. I will then briefly describe a host of methods that we have developed for phylogenetic network inference under the MSNC. The methods differ by the mathematical criterion they employ, the data they take as input, as well as the information they infer. I will also discuss practical issue facing phylogenetic network inference in practice. All methods are implemented and publicly available in the
PhyloNet software package (http://bioinfocs.rice.edu/phylonet).
BIO: Luay Nakhleh is the William and Stephanie Sick Dean of Engineering and Professor of Computer Science at Rice University in Houston, Texas. He received a B.Sc. degree in Computer Science (1996) from the Technion (Israel), a master’s degree in Computer
Science (1998) from Texas A&M University, and a Ph.D. degree in Computer Science (2004) from The University of Texas in Austin. He conducts research in the areas of bioinformatics and computational biology, focusing mainly on questions in evolutionary biology and genomics. Luay is a recipient of multiple awards including the Department of Energy CAREER award, the National Science Foundation CAREER award, the Sloan luay Fellowship, and the Guggenheim Fellowship.
https://www.cs.rice.edu/~nakhleh/",https://events.umich.edu/event/104311,"West Hall",340,"West Hall",,Physics,"Department of Statistics
Department of Statistics Seminar Series"
103732-21807704,"2023-02-24 12:00:00","2023-02-24 13:00:00","LAGS Seminar | Industrial Experience and Technical Discussion on Induced Polarization for Subsurface Characterization","Qiuzi Li (ExxonMobil)","Workshop / Seminar","Join Zoom Meeting
https://umich.zoom.us/j/95573161835
Meeting ID: 955 7316 1835
Passcode: 054136
There has been substantial interest in applying induced polarization phenomena, which broadly include electrode and membrane polarization, to characterize organic contamination and biogeochemical environments. The presence of dispersed electronically conductive grains contributes to the electrode polarization, which arises due to the capacitive charging of the Stern Layer at the conductor-electrolyte interface. On the other hand, the membrane polarization is driven by spatial inhomogeneity in the ionic transferences, i.e., the proportion of current carried by the cation vs. the anion. Several phenomenological models, semi-quantitative models, and models for particular pore shapes have been proposed for understanding induced polarization. Here, we developed theoretical frameworks to quantitatively explain electrode and membrane polarization based on insights from experiments on model systems. We obtained quantitative agreement between experiment and theory, not just for characteristic frequencies and amplitudes, but for the entire spectral shape of the phase angle between electric field and current density.
Biography: Dr. Qiuzi Li obtained BS in physics from Zhejiang University and Ph.D. in Theoretical Condensed Matter Physics from the University of Maryland-College Park. Her graduate research covered four distinct research areas: transport in disordered mesoscopic systems with a primary focus on graphene, quantum computation, three-dimensional topological insulators, and cold dipolar molecules. She is now pursuing a part-time MBA at Rutgers University concentrating on supply chain management and technology commercialization and entrepreneurship. Qiuzi joined ExxonMobil in 2013. Her primary research centers on the development of new methods for subsurface characterizations. Along the way, she invented a magneto-seismic method for detecting hydrocarbons and developed a fundamental understanding of the induced polarization exploration method. She has also developed a quantitative theory for modeling fluid flow effects on seismic, transport mechanisms in unconventional reservoir rocks, and oil recovery for mixed macro-and micro-pore carbonate reservoirs. Currently she leads the geological carbon storage program. In addition, Qiuzi served on the Committee on the Status of Women in Physics of American Physical Society. She also served as Chair of the New Professional Program group and the President of Asian Connection for Excellence (an Employee Resource Group at ExxonMobil). She recently awarded 2022 Distinguished Lectureship on Application of Physics by the American Physical Society.",https://events.umich.edu/event/103732,"West Hall",335,"West Hall",,"Physics
Science","Life After Grad School Seminars
Department of Physics"
105406-21811703,"2023-03-06 15:00:00","2023-03-06 16:00:00","HEP-Astro Seminar | The Hubble Tension and Theoretical, New-Physics Solutions","Tanvi Karwal (University of Pennsylvania)","Workshop / Seminar","The Hubble tension persists and continues to raise questions about our current understanding of the Universe. The discrepancy is greatest between two constraints on the current expansion rate of the Universe - one assuming LCDM and observing the early universe, and another directly measuring H0 in the local universe. I have worked extensively on understanding what this tension may indicate about the dark sector by building theoretical models to resolve this tension, the most successful being the early dark energy (EDE) scenario. My talk will go over the phenomenological features that allow EDE to successfully resolve the Hubble tension, challenges that lie ahead in finding the true underlying model of our Universe and how we may pursue cosmological concordance.",https://events.umich.edu/event/105406,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
105749-21812879,"2023-03-07 17:00:00","2023-03-07 18:00:00","Residual Estimates for an Anisotropic Swift-Hohenberg Equation","Zach Deiman","Workshop / Seminar","The Swift-Hohenberg equation, originally derived to model convective instabilities, serves as a useful model for pattern formation. Using a formal multiple scales expansion, we can derive an amplitude equation, known as the complex Ginzburg-Landau (CGL) equation, for an anisotropic Swift-Hohenberg (aSH) equation. Solutions to (CGL) can be used to approximate solutions to (aSH) on a larger domain, with arbitrarily small residual estimates. In this talk, we will demonstrate such estimates for an approximation in the space of bounded continuous functions on R^2. We will then define uniformly local Sobolev spaces and establish similar estimates in these more suitable spaces.",https://events.umich.edu/event/105749,"West Hall",335,"West Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics"
105055-21810651,"2023-03-08 15:00:00","2023-03-08 16:00:00","Department Colloquium | Atomic Clocks as Quantum Sensors","Andrei Derevianko (University of Nevada, Reno)","Workshop / Seminar","Atomic clocks are arguably the most accurate scientific instruments ever built. Modern clocks are astonishing timepieces guaranteed to keep time within a second over the age of the Universe. I will review the remarkable progress in atomic timekeeping and discuss a variety of applications of atomic clocks as quantum sensors. These applications range from measuring electric fields and geoids to dark matter and exotic physics searches. Massive entanglement of atomic ensembles offers an intriguing potential for improving the sensitivity even further. I will present our proposal on massive entanglement of millions of atoms with Rydberg gates.
A short bio: Andrei Derevianko is teaching quantum physics and related subjects at the University of Nevada, Reno (UNR). He has authored ~ 150 refereed publications in theoretical physics. He is a fellow of the American Physical Society, Simons fellow in theoretical physics, and a Fulbright scholar. Among a variety of research topics, he has contributed to the development of several novel classes of atomic clocks and to precision tests of fundamental symmetries with atoms and molecules. Recent interests include detection of ultralight dark matter with GPS.
Upon graduating from FizTech, he was involved with a computer startup in Moscow and then moved to the United States. He earned his Ph.D. at Auburn and did a postdoctoral work at Notre Dame and at the Harvard-Smithsonian Center for Astrophysics. He has been a University of Nevada-Reno faculty since 2000.",https://events.umich.edu/event/105055,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
105415-21811735,"2023-03-08 16:00:00","2023-03-08 17:30:00","Archaeological Proteins: Tracing the Spread of Dairy","Dr. Shevan Wilkin, Paleogenetics Group, Institute of Evolutionary Medicine, University of Zurich","Lecture / Discussion","Biomolecular analyses (proteins, stable isotopes, lipids, and DNA) have been integral in identifying the economic roles of domesticated animals in archaeological contexts. While analyses such as lipids, isotopes, and DNA are well-established, recently developed protein analysis offers new insights. The combination of species- and tissue-specific information provided by amino acid sequences have been critical in clarifying which animals, or animal products, were consumed by archaeological populations. While protein analysis offers new lines of evidence, working with ancient materials requires specific laboratory and data analysis protocols in order to authenticate the age and reliability of the results. Recently, this this method has been used to illuminate the spread of milk use on the Bronze Age Eurasian steppe and beyond. Through recently produced protein data, we can see that use of ruminant milk enabled long-distance Yamnaya migrations across arid steppic environments, and specifically, how milking practices traveled in tandem with expanding populations from the western Pontic-Caspian region to the far Eastern Steppe of Mongolia.
Snacks and refreshments to follow the lecture.",https://events.umich.edu/event/105415,"West Hall",411,"West Hall",,"Anthropology
Archaeology
Chemistry
Classical Studies","Museum of Anthropological Archaeology"
105847-21813104,"2023-03-13 15:00:00","2023-03-13 16:00:00","Virtual HEP-Astro Seminar | Overview of Dual-Readout Calorimetry Status and Development Plans For Future Electroweak Factories","Roberto Ferrari (INFN)","Workshop / Seminar","Meeting ID
954 2991 7490
https://umich.zoom.us/j/95429917490
Passcode123456
At present, hadronic shower energy measurements are heavily limited by the event-by-event fluctuations of the electromagnetic shower fraction. Based on the simultaneous measurement of scintillating (S) and Cherenkov (C) light, the dual-readout calorimetric technique is one of the solutions proposed for overcoming this problem and compensating for it, on an event-by-event basis. In this talk, we will quickly review the work done so far on dual-readout calorimeters and show their impressive potential, in particular when coupled with a highly granular readout system. On top of that, time measurements may complement the 2D imaging capabilities of a fibre-sampling calorimeter and provide information on the shower longitudinal profile. Finally, an electromagnetic dual-readout crystal section will open the door for measurements of electromagnetic showers with top-of-the-art energy resolution, without harming the hadronic performance. The development plans and the expected performance will be described in the context of the IDEA proto-experiment proposed for future circular electroweak factories (FCC-ee and CEPC).",https://events.umich.edu/event/105847,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
103126-21806151,"2023-03-14 15:00:00","2023-03-14 16:00:00","CM-AMO Seminar | Observation of a Massive Phason and THz Phonon-Driven Kerr Effects in a Weyl Charge Density Wave","Fahad Mahmood (University of Illinois Urbana-Champaign)","Workshop / Seminar","Understanding the fundamental collective excitations of an emergent many-body interacting system has been a crosscutting theme throughout many branches of physics. Key questions about the dynamics of these excitations in the presence of both many-body physics and topology are currently driving numerous major research efforts in quantum materials. One such material is (TaSe_4)_2I - a Weyl semimetal that undergoes charge density wave (CDW) ordering below 260 K. I will discuss two of our recent experiments using nonlinear light-matter interaction in the terahertz (THz) range to directly probe the dynamics of the collective excitations of (TaSe_4)_2I. I will first show how upon transient photoexcitation at low temperatures (TaSe_4)_2I strikingly emits coherent, narrow-band THz radiation. The frequency, polarization and temperature dependence of the emitted radiation imply the existence of a phason that acquires mass by coupling to long-range Coulomb interaction, giving a direct measurement of the Anderson-Higgs mechanism. Second, I will show our recent results using THz pump, IR Kerr probe spectroscopy on (TaSe_4)_2I to highlight how THz-driven phonons can induce a sizeable dynamic optical Kerr rotation in this otherwise time-reversal invariant system. I will briefly discuss both these results in the context of the predicted axion electrodynamics in (TaSe_4)_2I.",https://events.umich.edu/event/103126,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
106089-21813702,"2023-03-14 17:00:00","2023-03-14 18:00:00","Differential Geometry of Curves - An Elementary Introduction","Zakaria Zerrouki","Workshop / Seminar","This talk is an elementary introduction to the theory of differentiable curves in the two and three dimensions. The topics include:
- Curves in the plane and in space
- Arc length, curvature, torsion and the Frenet Frame
- The isoperimetric inequality for plane curve",https://events.umich.edu/event/106089,"West Hall",335,"West Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics"
105709-21812822,"2023-03-15 15:00:00","2023-03-15 16:00:00","Department Colloquium | Quantum Computing with Atoms","Christopher Monroe (Duke University and IonQ)","Workshop / Seminar","Trapped atomic ions are a leading physical platform for quantum computers, featuring qubits with essentially infinite idle coherence times and the highest purity quantum gate operations. Such atomic clock qubits are controlled with laser beams, allowing densely-connected and reconfigurable universal gate sets. The path to scale involves concrete architectural paths based on well-established protocols, from shuttling ions between QPU cores to modular photonic interconnects between multiple QPUs. I will summarize the state-of-the-art in these quantum computers in both academic and industrial settings, and summarize how they are being used for both scientific and commercial applications.",https://events.umich.edu/event/105709,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
104372-21808975,"2023-03-16 17:30:00","2023-03-16 19:30:00","The Michigan Anthropology Colloquia Series","""Decentering the Colonial Native Speaker"" by Anna Babel","Lecture / Discussion","The Department of Anthropology is proud to present
The Michigan Anthropology Colloquia series
""Decentering the Colonial Native Speaker""
By Anna Babel, Associate Professor of Hispanic Linguistics, The Ohio State University
Joined by Devin Grammon, University of Oregon
RSVP here: https://forms.gle/phut9Aeu6n2MdnLk6
Light refreshments provided
ABOUT THE LECTURE
In this talk, we contrast Eurocentric definitions of the “native speaker” with those of speakers of Quechua, an indigenous language of the Andes that is highly heteroglossic and typically centered on orality rather than written language. The native speaker construct has been thoroughly critiqued in fields such as second language acquisition and language policy and planning by demonstrating the ways in which this concept is racialized, reductionist, and used to validate the hegemony of powerful ethnic and political interests (e.g. Davies, 2003; Paikeday, 1985; Slavkov et al., 2022). Nonetheless, these critiques have tended to rely on implicit assumptions that connect an idealized native speaker to proficiency in a standardized national language via standard language ideologies (Bonfiglio, 2010; Bylin & Tingsell, 2022; Hackert, 2012; Lippi-Green, 1994). Recent critiques in linguistics have advanced the discussion of native speakerism by highlighting the construct’s links to colonialism and essentializing discourses, and advocating for a more specific, and less reductionist approach to the concept (e.g. Chen et al 2021; Birkeland et al forthcoming; Grammon & Babel 2021). Our research builds on these ideas and moves to decenter the colonial native speaker by investigating speakerhood beyond the western European nationalist tradition. We consider data from Peru and Bolivia to explore the concept of the native speaker in Quechua. In our data, drawn from recent interviews as well as long-term ethnographic fieldwork, family connections, place of birth, and language use play an important role in defining a “[native] speaker of Quechua.” Perhaps most strikingly, a Quechua speaker is centrally defined as bilingual or multilingual, and monolingual speakers are characterized as lacking something, objects of pity, and ultimately not fully competent human beings. We argue that it is important to consider - indeed, to center - approaches to speakerhood in multilingual, transnational indigenous communities that offer a contrast to discourses centered on language purism, nationalism and standard language ideologies. These differences point to important critiques that have so far been implicit in the literature on native speakerism. The ways that Quechua speakers define speakerhood lead us to question the naturalized linkages between idealized notions of racial and cultural purity, literacy, language standardization, and a modern national identity that are implicit in much of the academic literature in our fields.
ABOUT THE SPEAKER
Anna Babel is a sociolinguist and a linguistic anthropologist. Her research focuses on the relationship between language and social categories, particularly in settings of language contact. She has carried out long-term research in the Santa Cruz valleys of Bolivia, the setting of her ethnography, Between the Andes and Amazon. Her most recent work considers how we become aware of different ways of speaking, and conversely how our knowledge and beliefs about language influence the way that we speak. In addition to these areas of expertise, she teaches on the role of language in the construction of US and Latino/a/x identities.",https://events.umich.edu/event/104372,"West Hall","210 Linguistics Lab","West Hall",,Anthropology,"Department of Anthropology"
104313-21808814,"2023-03-17 10:00:00","2023-03-17 11:00:00","Statistics Department Seminar Series: Fan Li, Professor, Department of Statistical Science, Duke University","""Addressing Selection Bias in Cluster Randomized Trials""","Workshop / Seminar","Abstract: In pragmatic cluster randomized experiments, units are often recruited after the random cluster assignment. This can lead to post-randomization selection bias, inducing systematic differences in baseline characteristics of the recruited patients between intervention and control arms. We clarify that in such situations there are two different causal estimands of average treatment effects, one on the overall population and one on the recruited population. We use principal stratification to clarify the intrinsic difference between these estimands and the bias of the standard intention-to-treat analysis . We show that under the assumption of ignorable recruitment, the average treatment effect on the recruited population can be consistently estimated from the recruited sample, via either regression adjustment or inverse probability weighting. While the average treatment effect on the overall population is generally not identifiable from the observed sample alone, a meaningful weighted estimand on the overall population can be consistently estimated via applying a simple weighting scheme to the recruited sample. This estimand corresponds to the subpopulation of units who would be recruited into the study regardless of the assignment. We also develop a sensitivity analysis method for checking the ignorable recruitment assumption. We illustrate the proposed methods via a real world application in cardiology.
https://www2.stat.duke.edu/~fl35/",https://events.umich.edu/event/104313,"West Hall",340,"West Hall",,Physics,"Department of Statistics
Department of Statistics Seminar Series"
105789-21812948,"2023-03-20 15:00:00","2023-03-20 16:00:00","HEP-Astro Seminar | The Snowball Chamber: Opportunities With Supercooled Water for Dark Matter, Neutrinos, and General Particle Detection","Matthew Szydagis (University at Albany State University of New York)","Workshop / Seminar","The snowball chamber is analogous to the bubble and cloud chambers in that it relies on a phase transition, but it is new to high-energy particle physics. The concept of the snowball chamber relies on supercooled water, which can remain metastable for long time periods in a sufficiently clean and smooth container (on the level of the critical radius for nucleation). The results gleaned from the first prototype setup (20 grams) will be reviewed, as well as plans for the future, with an eye to future deployment of a larger (kg-scale) device underground for direct detection of dark matter WIMPs (Weakly Interacting Massive Particles), with a special focus on low-mass (GeV-scale) WIMPs, capitalizing on the presence of Hydrogen, which could potentially also lead to world-leading sensitivity to spin-dependent-proton interactions for O(1 GeV/c^2)-mass WIMPs and coherent neutrino scattering. Supercooled water also has the potential advantage of a sub-keV energy threshold for nuclear recoils, but this remains an atmospheric chemistry prediction that must be verified by careful measurements.",https://events.umich.edu/event/105789,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
106175-21813891,"2023-03-20 16:00:00","2023-03-20 17:00:00","Special Physics Colloquium | New Paradigms in Quantum Computing: Beyond Quantum Circuits with Trapped-Ion Qubits","Or Katz, Departments of ECE and Physics (Duke University)","Workshop / Seminar","If you can't join us in person, the colloquium is available via Zoom: https://umich.zoom.us/j/94363328065 Meeting ID: 943 6332 8065
Trapped ions are a leading quantum technology for quantum computation and simulation, with the capability to solve computationally hard problems and deepen our understanding of complex quantum systems. The quantum circuit model is the central paradigm for quantum computation, enabling the realization of various quantum algorithms by application of multiple one- and two-qubit entangling operations. However, the typical number of entangling operations required by this model increases exponentially with the number of qubits, making it difficult to apply to many problems.
In my presentation, I will discuss new methods for realizing quantum gates and simulations that go beyond the quantum circuit model. I will first describe a single-step protocol for generating native, -body interactions between trapped-ion spins, using spin-dependent squeezing. Next, I will present a preparation of novel phases of matter using simultaneous and reconfigurable spin-spin interactions. Lastly, I will explore new avenues to harness the long-lived phonon modes in trapped-ion crystals for simulating complex bosonic and spin-boson models that are difficult to solve using classical methods. The presented techniques could push the performance of trapped-ion systems to solve problems that are currently beyond their reach.",https://events.umich.edu/event/106175,"West Hall",340,"West Hall",,"Faculty
Graduate Students
Physics
Postdoctoral Research Fellows","Department of Physics
The Center for the Study of Complex Systems
Applied Physics
LSA Biophysics"
86568-21634905,"2023-03-21 15:00:00","2023-03-21 16:00:00","CM-AMO Seminar | Designing “Perfect” Spin Liquids Candidates","Sara Haravifard (Duke University)","Workshop / Seminar","Quantum Spin Liquid (QSL) is one of the most astonishing states of matter which was theoretically predicted decades ago. In such a state the spins appear disordered while they form a novel entanglement, which if harnessed could be used for future technological advancements such as quantum computing. Despite the outpour of activities in pursuit of designing and characterizing perfect QSL candidates, these experimental efforts have proven challenging. In this talk I will review some of these challenges and discuss our recent efforts to overcome them and provide a deeper understanding for this fascinating state of matter.",https://events.umich.edu/event/86568,"West Hall",335,"West Hall",,"Physics
Science","Department of Physics
CM-AMO Seminars"
106194-21813911,"2023-03-22 15:00:00","2023-03-22 16:00:00","Department Colloquium | Brave New World of Numerical Relativity","Deirdre Shoemaker (The University of Texas at Austin)","Workshop / Seminar","After decades of preparation, the era of gravitational wave astronomy has begun. The gravitational wave detectors, LIGO and Virgo, have published a catalog of 90 events of coalescing compact objects including black holes and neutron stars. I will present the role that numerical relativity played in the unveiling of the gravitational wave sky and anticipate how it might improve our understanding of gravity as the detectors improve.",https://events.umich.edu/event/106194,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
106210-21813927,"2023-03-23 15:00:00","2023-03-23 16:00:00","Interdisciplinary QC-CM Seminar | Density Function Theory (DFT) and Quantum Monte Carlo (QMC) Methods for Gas Phase Chemistry and Magnetic Materials","Sandeep Sharma (University of Colorado Boulder)","Workshop / Seminar","To obtain accurate reaction barriers for gas phase chemistry the most widely used and reliable method is coupled cluster (CCSD(T)) theory. Although this method was developed more than 4 decades ago, it has been difficult to come up with alternatives that outperform it. In this talk I will present a QMC method, called auxiliary field quantum Monte Carlo, that is able to systematically improve upon CCSD(T) and deliver chemical accuracy. I will review recent developments that have enabled this, including the ability to: cheaply and systematically improve the quality of results, obtain properties (other than just energies) and scale up to large systems at a cost that is linear in the system size.
In the second part of the talk I will present our recent work on understanding magnetism, which is a ubiquitous phenomenon that is often found in systems ranging from metalloenzymes to correlated quantum materials. However, describing it theoretically with sufficient accuracy remains one of the outstanding challenges for electronic structure theory. The difficulty can be traced back to the simultaneous presence of strong electron correlation and large relativistic effects. In extended systems, the presence of an Avogadro's number of electrons further complicates the matter. I will begin by describing some of the algorithms that have been developed in my group to tackle these challenges. For example, we can now perform efficient hybrid DFT calculations in periodic systems, we can also treat relativistic effects such as spin orbit coupling on an equal footing with electron correlation. By using these techniques in concert, we will study the electronic structure of magnetic systems.",https://events.umich.edu/event/106210,"West Hall",335,"West Hall",,"Physics
Science","Interdisciplinary QC/CM Seminars
Department of Physics"
104314-21808816,"2023-03-24 10:00:00","2023-03-24 11:00:00","Statistics Department Seminar Series: Richard Samworth, Professor of Statistical Science, Director of Statistical Laboratory, University of Cambridge","""Optimal subgroup selection""","Workshop / Seminar","Abstract: In clinical trials and other applications, we often see regions of the feature space that appear to exhibit interesting behaviour, but these observed phenomena may not reflected at the population level. Focusing on a regression setting, we consider the subgroup selection challenge of identifying a region of the feature space on which the regression function exceeds a pre-determined threshold. We formulate the problem as one of constrained optimisation, where we seek a low-complexity, data-dependent selection set on which, with a guaranteed probability, the regression function is uniformly at least as large as the threshold; subject to this constraint, we would like the region to contain as much mass under the marginal feature distribution as possible. This leads to a natural notion of regret, and we determine the minimax optimal rate for this regret in both the sample size and the Type I error probability. The rate involves a delicate interplay between the different problem parameters. Finally, we expand the scope of our previous results by illustrating how they may be generalised to a treatment and control setting, where interest lies in the heterogeneous treatment effect.
https://www.statslab.cam.ac.uk/~rjs57/",https://events.umich.edu/event/104314,"West Hall",340,"West Hall",,Physics,"Department of Statistics
Department of Statistics Seminar Series"
106133-21813794,"2023-03-24 15:00:00","2023-03-24 16:00:00","HET Seminar | Evolution of Self-Interacting Dark Matter Halos","Kimberly Boddy (UTexas)","Lecture / Discussion","Abstract: Large self interactions between dark matter particles alter the predicted properties of dark matter halos and may help address small-scale structure issues, while maintaining the successes of standard cold dark matter at large scales. Self interactions allow for efficient heat transfer within a halo, which can be modeled using a gravothermal fluid approximation. In this talk, I will discuss how the choice of the particle physics model for self interactions, as well as the environment of the halo, impacts the phases of halo evolution.",https://events.umich.edu/event/106133,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Lecture
Physics
Science","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
105612-21812268,"2023-03-24 16:00:00","2023-03-24 17:30:00","The Michigan Anthropology Colloquia Series","""Mind the Gap: Human origins and other poorly known events of the Late Miocene of Africa"" by James Rossie","Lecture / Discussion","The Department of Anthropology proudly presents
The Michigan Anthropology Colloquia series
""Mind the Gap: Human origins and other poorly known events of the Late Miocene of Africa""
By James Rossie, Associate Professor of Anthropology, Stony Brook University
In-Person: 4PM, 411 West Hall
Virtually: https://umich.zoom.us/j/92496167134
Rossie will talk about his field research at Lake Turkana, and occasionally with the Baringo Paleontological Research Project, aimed at improving our knowledge of ape and human evolution between 14 and 6 million years ago.
ABOUT THE SPEAKER
Raised in the North Country of New York, James Rossie took an interest in human evolution in college, went to the Koobi Fora Field School in 1995, and then to graduate school at Yale where he was trained by Andrew Hill. While there he met many excellent people, including John Kingston and Laura MacLatchy. After a 3 year post-doc at the Carnegie Museum, Rossie joined the faculty at Stony Brook in 2005. He likes to summer at Lake Baringo and Lake Turkana.",https://events.umich.edu/event/105612,"West Hall",411,"West Hall",,"AEM Featured
Africa
Anthropology
Biology
Ecology And Evolutionary Biology","Department of Anthropology"
104377-21808980,"2023-03-27 15:00:00","2023-03-27 16:30:00","The Michigan Anthropology Colloquia Series","""Crossing a Line: Laws, Violence & Roadblocks to Palestinian Political Expression"" by Amahl Bishara","Lecture / Discussion","The Department of Anthropology is proud to present
The Michigan Anthropology Colloquia Series
*Crossing a Line: Laws, Violence & Roadblocks to Palestinian Political Expression*
Amahl Bishara
Associate Professor and Chair, Anthropology
Tufts University
The event will be offered in-person and virtually.
Attend on Zoom: https://umich.zoom.us/j/92496167134
Palestinians living on different sides of the Green Line make up approximately one-fifth of Israeli citizens and about four-fifths of the population of the West Bank. In both groups, activists assert that they share a single political struggle for national liberation. Yet, obstacles inhibit their ability to speak to each other and as a collective. Geopolitical boundaries fragment Palestinians into ever smaller groups. Through ethnography, Bishara enters these distinct environments for political expression and action of Palestinians who carry Israeli citizenship and Palestinians subject to Israeli military occupation in the West Bank, and considers how Palestinians are differently impacted by dispossession, settler colonialism, and militarism. Bishara looks to sites of political practice—journalism, historical commemorations, street demonstrations, social media, in prison, and on the road—to analyze how Palestinians create collectivities in these varied circumstances. She draws on firsthand research, personal interviews, and public media to examine how people shape and reshape meanings in circumstances of constraint. In considering these different environments for political expression and action, Bishara illuminates how expression is always grounded in place—and how a people can struggle together for liberation even when they cannot join together in protest.
Amahl Bishara is Associate Professor and Chair of the Anthropology Department at Tufts University. She is the author of Crossing a Line: Laws, Violence, & Roadblocks to Palestinian Political Expression (Stanford 2022), about different conditions of expression for Palestinian citizens of Israel and Palestinians in the West Bank. She also writes about popular refugee politics in the West Bank. Her first book, Back Stories: U.S. News and Palestinian Politics (Stanford University Press 2013), is an ethnography of the production of U.S. news during the second Palestinian Intifada. She is the president of the Middle East Section of the American Anthropological Association.",https://events.umich.edu/event/104377,"West Hall",411,"West Hall",,Anthropology,"Department of Anthropology"
106447-21814283,"2023-03-27 16:00:00","2023-03-27 17:00:00","Special Department of Physics Colloquium | Interactive many-body quantum dynamics","Romain Vasseur (University of Massachusetts, Amherst)","Workshop / Seminar","Zoom link:
https://umich.zoom.us/j/99916677200
Meeting ID: 999 1667 7200
One tap mobile
+16468769923,,99916677200# US (New York)
+16469313860,,99916677200# US
While many-body quantum physics has traditionally focused on the properties of cold matter in thermal equilibrium, emerging noisy intermediate scale quantum (NISQ) platforms allow access to far-from-equilibrium dynamics with local space and time control over interactions. In this new era of “interactive quantum dynamics,” a key challenge is to identify universal features of non-equilibrium quantum dynamics, transport and many-body entanglement. In this talk, I will discuss new types of non-equilibrium quantum phases of matter and phase transitions, with an emphasis on the emergence of universality far from thermal equilibrium. In particular, I will focus on the recently discovered “entanglement phase transitions” that occur in monitored quantum systems, and separate phases characterized by the amount of quantum information that can be extracted from measurements. I will also highlight emerging connections between quantum entanglement, quantum communication theory and classical statistical physics.",https://events.umich.edu/event/106447,"West Hall",340,"West Hall",,"Faculty
Graduate Students
Physics","Department of Physics
The Center for the Study of Complex Systems
Applied Physics
LSA Biophysics"
103127-21806152,"2023-03-28 15:00:00","2023-03-28 16:00:00","CM-AMO Seminar | The good, the bad and the strange: unconventional metallic behavior in the vicinity of Mott insulators","Debanjan Chowdhury (Cornell University)","Workshop / Seminar","In recent years, we have witnessed remarkable experimental breakthroughs in uncovering the intriguing properties of correlated metals in the vicinity of Mott transitions. Describing these phenomena theoretically remains an open challenge. This talk will focus on three recent examples of puzzling electronic behavior near Mott insulating phases and address the various conundrums. In the first part of the talk, I will discuss the microscopic origin of an unconventional T-linear resistivity with Planckian scattering in a quasi-two-dimensional “good” metal with long mean-free path, consisting of highly conducting metallic and Mott insulating layers, respectively. In the second part, I will address the origin of a low-temperature “bad” metallic behavior in the vicinity of a continuous bandwidth-tuned metal-insulator transition in a moiré semiconductor. I will end by presenting some new theoretical insights into the experimental observation of an anomalous particle-hole continuum and overdamped plasmon in the density response of cuprate “strange” metals.",https://events.umich.edu/event/103127,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
106439-21814275,"2023-03-29 15:00:00","2023-03-29 16:00:00","Department Colloquium | How to do particle physics in a climate emergency?","Ken Bloom (University of Nebraska)","Workshop / Seminar","The pursuit of particle physics, or any kind of discovery-driven research, requires a stable and prosperous society. Today, our society is increasingly threatened by global climate change. Human-influenced climate change has already impacted weather patterns, and global warming will only increase unless deep reductions in emissions of CO2 and other greenhouse gases are achieved. Current and future activities in particle physics need to be considered in this context, either on the moral ground that we have a responsibility to leave a habitable planet to future generations, or on the more practical ground that, because of their scale, particle physics projects and activities will be under scrutiny for their impact on the climate. I will discuss several contexts in which particle physics has an impact on greenhouse gas emissions, and how our field can contribute to a more sustainable future.",https://events.umich.edu/event/106439,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
106213-21813929,"2023-03-30 15:00:00","2023-03-30 16:00:00","Interdisciplinary QC-CM Seminar | Many-Electron Effects and Light-Matter Interactions at Nanoscale","Li Yang (Washington University in St Louis)","Workshop / Seminar","In this talk, I will start from introducing a general picture of light-matter interactions in nanoscale materials and the first-principles many-body perturbation approach for calculating excited states, such as quasiparticles and excitons. Then I will focus on many-electron interactions in two-dimensional (2D) moiré crystals. We propose a way to enhance the crucial moiré potential by manipulating the coupling between quasiparticles and carrier plasmons. Our calculation shows that this mechanism can effectively enhance the quasiparticle moiré potential by a few times of magnitude, providing an excellent opportunity to control and observe correlated Hubbard physics in 2D moiré crystals. In the second part of the talk, I will switch to the second-order light-matter interactions in PT-symmetric materials. Using the quantum perturbation theory, we predict that light with different polarizations can selectively drive sizable charge current or pure spin current in emerging antiferromagnetic 2D structures or topological materials.",https://events.umich.edu/event/106213,"West Hall",335,"West Hall",,"Physics
Science","Interdisciplinary QC/CM Seminars
Department of Physics"
106492-21814347,"2023-03-30 16:00:00","2023-03-30 17:30:00","Anthropologizing Eastern Europe: A Brief History of Forming an Ethnographic Region","Sociocultural Workshop with Katherine Verdery","Workshop / Seminar","Sociocultural Workshop:
Anthropologizing Eastern Europe:
A Brief History of Forming an Ethnographic Region
Katherine Verdery
Julien J. Studley Faculty Scholar and Distinguished Professor Emerita, Anthropology
City University of New York
Katherine Verdery, who obtained her Ph.D. at Stanford University, has conducted field research in Romania since 1973, initially focusing on the political economy of social inequality, ethnic relations, and nationalism. With the changes of 1989, her work has shifted to problems of the transformation of socialist systems, specifically changing property relations in agriculture. From 1993 to 2000, she did fieldwork on this theme in a Transylvanian community; the resulting book, The Vanishing Hectare: Property and Value in Postsocialist Transylvania (2003) received the J. R. Staley Prize in Anthropology. She completed a large collaborative project with Gail Kligman (UCLA) and a number of Romanian scholars on the opposite process, the formation of collective and state farms in Romania during the 1950s. The resulting book, Peasants under Siege: The Collectivization of Romanian Agriculture, 1949–1962 (2011), received a number of prizes in Slavic studies and in sociology.
Verdery’s teaching interests include contemporary and socialist Eastern Europe, the anthropology of property, and time and space. Recent books include ""Secrets and Truths: Ethnography in the Archive of the Romanian Secret Police"" (Central European University Press, 2014) and ""My Life as a Spy: Investigations In a Secret Police File"" (Duke University Press, 2018).",https://events.umich.edu/event/106492,"West Hall",210,"West Hall",,"Anthropology
eastern europe
European
European Studies","Department of Anthropology
Center for Russian, East European, and Eurasian Studies
Weiser Center for Europe and Eurasia"
105016-21810585,"2023-03-31 10:00:00","2023-03-31 11:00:00","Statistics Department Seminar Series: Susan Murphy, Mallinckrodt Professor of Statistics and of Computer Science, Radcliffe Alumnae Professor at the Radcliffe Institute, Harvard University",,"Workshop / Seminar","""Inference for Longitudinal Data After Adaptive Sampling""
Abstract: Adaptive sampling methods, such as reinforcement learning (RL) and bandit algorithms, are increasingly used for the real-time personalization of interventions in digital applications like mobile health and education. As a result, there is a need to be able to use the resulting adaptively collected user data to address a variety of inferential questions, including questions about time-varying causal effects. However, current methods for statistical inference on such data (a) make strong assumptions regarding the environment dynamics, e.g., assume the longitudinal data follows a Markovian process, or (b) require data to be collected with one adaptive sampling algorithm per user, which excludes algorithms that learn to select actions using data collected from multiple users. These are major obstacles preventing the use of adaptive sampling algorithms more widely in practice. In this work, we proved statistical inference for the common Z-estimator based on adaptively sampled data. The inference is valid even when observations are non-stationary and highly dependent over time, and (b) allow the online adaptive sampling algorithm to learn using the data of all users. Furthermore, our inference method is robust to miss-specification of the reward models used by the adaptive sampling algorithm. This work is motivated by our work in designing the Oralytics oral health clinical trial in which an RL adaptive sampling algorithm will be used to select treatments, yet valid statistical inference is essential for conducting primary data analyses after the trial is over.
http://people.seas.harvard.edu/~samurphy/",https://events.umich.edu/event/105016,"West Hall",340,"West Hall",,Physics,"Michael Woodroofe Lecture Series
Department of Statistics
Department of Statistics Seminar Series"
106538-21814437,"2023-03-31 14:00:00","2023-03-31 15:00:00","HET Seminar | Scattering on the worldsheet of the QCD string","Sergei Dubovsky (NYU)","Lecture / Discussion",TBD,https://events.umich.edu/event/106538,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics
Science","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
106524-21814404,"2023-03-31 16:00:00","2023-03-31 17:00:00","Special Department Colloquium | Quantum Diamond Sensors — Best of Both Worlds","Ronald Walsworth (University of Maryland)","Workshop / Seminar","The nitrogen–vacancy (NV) quantum defect in diamond is a leading modality for magnetic, electrical, temperature, and pressure sensing with high spatial resolution and wide field-of-view, operating under both ambient and extreme conditions. This quantum sensing technology has diverse applications across the physical and life sciences — from probing magnetic materials to biomedical diagnostics. I will provide an overview of quantum diamond sensors and their many applications.",https://events.umich.edu/event/106524,"West Hall",335,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
103488-21807340,"2023-04-03 15:00:00","2023-04-03 16:30:00","The Michigan Anthropology Colloquia Series","""Historical and contemporary anthropogenic effects on mammal communities"" by Lydia Beaudrot","Lecture / Discussion","The Department of Anthropology is proud to present
The Michigan Anthropology Colloquia series
""Historical and contemporary anthropogenic effects on mammal communities""
Lydia Beaudrot, Rice University
This event will be presented both in-person and virtually.
Attend on Zoom: https://umich.zoom.us/j/92496167134
Lydia Beaudrot is an Assistant Professor of Biosciences and a faculty member in the Program in Ecology and Evolutionary Biology at Rice University. Her research group uses observational data and statistical modeling to address research questions at the interface of ecological theory and conservation biology, focusing particularly on tropical forest mammal communities. Beaudrot earned her PhD in Ecology from the University of California, Davis. Afterwards, she worked as a postdoc at Conservation International for the Tropical Ecology Assessment and Monitoring Network (TEAM). Beaudrot was then a member of the Michigan Society of Fellows in the Department of Ecology and Evolutionary Biology at the University of Michigan for three years before joining the faculty at Rice.",https://events.umich.edu/event/103488,"West Hall",411,"West Hall",,"AEM Featured
Anthropology","Department of Anthropology"
106643-21814617,"2023-04-03 16:00:00","2023-04-03 17:00:00","Special CM-AMO Seminar | Optically-active solid-state spins in photonic platforms for quantum science and technology","Demitry Farfurnik (University of Maryland)","Workshop / Seminar","Optically-active solid-state spin systems can offer remarkable single photon emission properties (brightness and indistinguishability), which makes them useful for developing photonic quantum simulators and building blocks of quantum networks. In this talk, I will present the efforts of studying the fundamental physics of optically-active spin systems and integrating these systems in photonic platforms for quantum technologies. First, I will describe all-optical implementations of NMR-inspired protocols for controlling the quantum state of optically-active spins and for the diffraction-limited probing of their nuclear environment. Then, I will discuss the process of coupling optically-active spins to photonic cavities, which provides spin-dependent optical switching capabilities. Finally, I will focus on the applications of spins in photonic platforms for simulating quantum dynamics under complex Hamiltonians, as well as toward the demonstration of photonic repeaters for the efficient distribution of quantum information.",https://events.umich.edu/event/106643,"West Hall",340,"West Hall",,"Faculty
Graduate Students
Physics","CM-AMO Seminars
Department of Physics"
103128-21806153,"2023-04-04 15:00:00","2023-04-04 16:00:00","CM-AMO Seminar | Chiral phonon-spin coupling in hexagonal lattices","Hanyu Zhu (Rice University)","Workshop / Seminar","The electronic and magnetic properties of solids are fundamentally determined by the crystal structures. When the structure keeps evolving, the properties are usually determined by the instantaneous lattice configurations, but this may not always be true. When phonons are coherently excited in solids, the atoms oscillate back and forth around their equilibrium positions, and one would expect the perturbation on electronic properties to largely cancel out. But a qualitative change might be possible with atomic motions called “chiral phonons”, which break time-reversal symmetry and would in principle affect all properties protected by such symmetry. Chiral phonons with quantized angular momentum are simply guaranteed by multi-fold rotational symmetry, and thus are rather common in materials and have been predicted to cause unexpected magnetic, topological, and transport phenomena. In this talk, I will first briefly introduce the discovery of chiral phonons in two-dimensional (2D) semiconductors, which exhibit spin-valley locking and chiral electron-phonon coupling. I will then discuss the general properties of chiral phonons originating from time-reversal symmetry breaking, and give an example on the optical control and the magnetic properties of chiral phonons in rare earth halides. Finally, I will introduce quantum coherent spin-phonon coupling in 2D antiferromagnets, leading to magnon-phonon hybridization, nontrivial topology, and chiral edge states. Together, these phenomena demonstrate a new paradigm of dynamic structural-property relationship in quantum materials.
Bio: Dr Hanyu Zhu is an assistant professor of Materials Science and NanoEngineering at Rice University. He earned his B.S. in Mathematics and Physics in Tsinghua University in China, when he got into the field of nanomaterials. He obtained his Ph.D. in Applied Science and Technology in the University of California at Berkeley for studying electromechanics of atomically thin crystals. After postdoctoral research at Berkeley developing novel optical spectroscopy for phonons, he started the Emerging Quantum and Ultrafast Materials Lab in 2018, with a focus on optical control of quantum materials. He has a joint appointment in the department of Physics and Astronomy, and is a member of the Rice Center for Quantum Materials as well as the Rice Quantum Initiative. He received the ORAU Ralph E. Powe Junior Faculty Enhancement Award in 2019 and the NSF CAREER Award in 2023.",https://events.umich.edu/event/103128,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
107123-21815371,"2023-04-04 17:00:00","2023-04-04 18:00:00","A look at Iterative Methods via Cubic NLS","Katja Vassilev","Workshop / Seminar","In this talk, we will explore the Wave Kinetic Equation for the Cubic Nonlinear Schrodinger Equation (NLS). We will begin with a brief overview of the history of Wave Turbulence Theory and then discuss how the problem (for the NLS and other PDEs) can be reformulated into a counting problem on Trees/Molecules. We will also directly compute the first few iterates for the NLS to see how the Wave Kinetic Equation arises.",https://events.umich.edu/event/107123,"West Hall",335,"West Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics"
106966-21815058,"2023-04-05 15:00:00","2023-04-05 16:00:00","Department Colloquium | The Heavyweight W boson - an Upset to the Standard Model of Particle Physics","Ashutosh Kotwal (Duke University)","Workshop / Seminar","The Standard Model of particle physics has been a crowning achievement of fundamental physics, culminating in the discovery of the Higgs boson in 2012. As a quantum theory of the building blocks of matter and forces, it has been one of the most successful theories in science. The recent measurement of the mass of the W boson disagrees with the theory prediction. This upset to the Standard Model may point towards exciting new discoveries in particle physics in the coming years. We will discuss the Standard Model, the crucial role of the W boson, and how it has become the harbinger of new laws of nature.",https://events.umich.edu/event/106966,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
107124-21815372,"2023-04-06 15:00:00","2023-04-06 16:00:00","Interdisciplinary QC-CM Seminar | From Biological Intelligence to Artificial General Intelligence: Challenges, Opportunities and Methodologies","Paul Bogdan (University of Southern California)","Workshop / Seminar","Brains build compact models of the world from just a few noisy and conflicting observations. They predict events via memory-based analogies even when resources are limited. The ability of biological intelligence to generalize and complete a wide range of unknown heterogeneous tasks calls for a comprehensive understanding of how networks of interactions among neurons, glia, and vascular systems enable human cognition. This will serve as a basis for advancing the design of artificial general intelligence (AGI). In this talk, we introduce a series of novel mathematical tools which can help us reconstruct networks among neurons, infer their objectives, and identify their learning rules.
To decode the network structure from very scarce and noisy data, we develop the first mathematical framework which identifies the emerging causal fractal memory phenomenon in the spike trains and the neural network topologies. We show that the fractional order operators governing the neuronal spiking dynamics provide insight into the topological properties of the underlying neuronal networks and improve the prediction of animal behavior during cognitive tasks. In addition to this, we propose a variational expectation-maximization approach to mine the optical imaging of brain activity and reconstruct the neuronal network generator, namely the weighted multifractal graph generator. Our proposed network generator inference framework can reproduce network properties, differentiate varying structures in brain networks and chromosomal interactions, and detect topologically associating domain regions in conformation maps of the human genome. Moreover, we develop a multiwavelet-based neural operator in order to infer the objectives and learning rules of complex biological systems. We thus learn the operator kernel of an unknown partial differential equation (PDE) from noisy scarce data. For time-varying PDEs, this model exhibits 2-10X higher accuracy than state-of-the-art machine learning tools.
Bio: Paul Bogdan is the Jack Munushian Early Career Chair and Associate Professor in the Ming Hsieh Department of Electrical and Computer Engineering at University of Southern California. He received his Ph.D. degree in Electrical & Computer Engineering at Carnegie Mellon University. His work has been recognized with a number of honors and distinctions, including the 2021 DoD Trusted Artificial Intelligence (TAI) Challenge award, the USC Stevens Center 2021 Technology Advancement Award for the first AI framework for SARS-CoV-2 vaccine design, the 2019 Defense Advanced Research Projects Agency (DARPA) Director’s Fellowship award, the 2018 IEEE CEDA Ernest S. Kuh Early Career Award, the 2017 DARPA Young Faculty Award, the 2017 Okawa Foundation Award, the 2015 National Science Foundation (NSF) CAREER award, the 2012 A.G. Jordan Award from Carnegie Mellon University for an outstanding Ph.D. thesis and service, and several best paper awards. His research interests include cyber-physical systems, new computational cognitive neuroscience tools for deciphering biological intelligence, the quantification of the degree of trustworthiness and self-optimization of AI systems, new machine learning techniques for complex multi-modal data, the control of complex time-varying networks, the modeling and analysis of biological systems and swarms, new control techniques for dynamical systems exhibiting multi-fractal characteristics, performance analysis and design methodologies for heterogeneous manycore systems.",https://events.umich.edu/event/107124,"West Hall",335,"West Hall",,"Physics
Science","Interdisciplinary QC/CM Seminars
Department of Physics"
105011-21810580,"2023-04-07 10:00:00","2023-04-07 11:00:00","Statistics Department Seminar Series: Yen-Chi Chen, Assistant Professor, Department of Statistics, University of Washington","""Pattern Graphs: a Graphical Approach to Nonmonotone Missing Data""","Workshop / Seminar","Abstract: We introduce the concept of pattern graphs--directed acyclic graphs representing how response patterns are associated. A pattern graph represents an identifying restriction that is nonparametrically identified/saturated and is often a missing not at random restriction. We introduce a selection model and a pattern mixture model formulation using the pattern graphs and show that they are equivalent. A pattern graph leads to an inverse probability weighting estimator as well as an imputation-based estimator. We also study the semi-parametric efficiency theory and derive a multiply-robust estimator using pattern graphs.
https://stat.uw.edu/about-us/people/yen-chi-chen",https://events.umich.edu/event/105011,"West Hall",340,"West Hall",,Physics,"Department of Statistics
Department of Statistics Seminar Series"
107147-21815434,"2023-04-07 12:00:00","2023-04-07 13:00:00","LAGS Seminar | Preparing Technical Specialists for Management / Leadership Responsibilities","James Hylko (U-M Physics Alumnus)","Workshop / Seminar","In-Person Seminar or
Join Zoom Meeting
https://umich.zoom.us/j/95573161835
Meeting ID: 955 7316 1835
Passcode: 054136
During our professional careers, we may find ourselves transitioning from a technical specialist fixed in a particular area to leading a project, or serving as a department manager. However, unless a company has a specific managerial succession or leadership development program, management / leadership styles are often learned by mirroring early personal experiences, typically involving family, teachers, coaches, and supervisors. Although success can be quantified by achieving schedule and budget milestones, is the manager / leader mystique of success attributed to natural talent, timing, mentoring, or a combination of these factors? This presentation discusses the practical core elements that contribute to becoming an effective manager and visionary leader.",https://events.umich.edu/event/107147,"West Hall",335,"West Hall",,"Free
Graduate Students
Physics","Life After Grad School Seminars
Department of Physics"
107046-21815191,"2023-04-07 15:00:00","2023-04-07 16:00:00","HET Seminar | Top Down Topological Holography and Twists on Twistor Space","Natalie Paquette (University of Washington)","Lecture / Discussion","I will discuss recent work in collaboration with Kevin Costello and Atul Sharma. Aspects of the holographic correspondence can be understood mathematically through a framework called twisted holography, which has been applied to AdS/CFT to compute certain protected correlators. In this talk we will apply these ideas to describe a new holographic duality for a bulk theory in an asymptotically flat spacetime which arises from studying twisted holography on twistor space. The ``boundary'' 2d chiral algebra, which is dual to the algebra of bulk asymptotic symmetries, can be described using a mathematical technique called Koszul duality. Alternatively, the 4d and 2d theories are independently defined from top-down string theoretic reasoning, and we match OPEs with collinear limits of scattering amplitudes in the planar limit as a check.",https://events.umich.edu/event/107046,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
107385-21815936,"2023-04-12 15:00:00","2023-04-12 16:00:00","Department Colloquium | Quantum Simulation, Sensing, and Computation With Ultracold Atoms","Dan Stamper-Kurn (University of California Berkeley)","Workshop / Seminar","Ultracold atomic gases are perhaps the coldest matter in the universe, reaching temperatures below one nano-kelvin. At these low temperatures, noise is ironed out and the quantum mechanical properties of atoms, not only of their internal atomic states but also of their center-of-mass motion, become accessible and visible. I will describe applications of this ultracold quantum material in the areas of quantum simulation, sensing, and computation. Specifically, I will show how quantum gases far from equilibrium allow us to probe geometric singularities in band structure, a quantum simulation of condensed matter. I will describe how single atoms, trapped tightly within optical tweezers, can be serve as quantum sensors within a scanning-probe microscope of optical fields. Finally, I will explain how cavity-enhanced detection allows us to make mid-circuit measurements within an atoms-based quantum computing platform, a step toward quantum error correction. And what's next? Feedback control of quantum systems? Electromagnetic vacuum fluctuations serving as a chemical catalyst? Telecom-frequency optical clocks? Simulation of flat-band ferromagnetism? Perhaps all of the above.",https://events.umich.edu/event/107385,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics
Undergrad Physics Events"
106573-21814484,"2023-04-13 14:30:00","2023-04-13 15:30:00","Special Interdisciplinary QC-CM Seminar | Manipulating Light-Matter Interactions in Structured Dielectric Media","Eric Seabron (Howard University, Department of Electrical Engineering)","Workshop / Seminar","Next generation information platforms based on planar integrated photonics and free space optics have shown significant promise for overcoming the performance bottlenecks of traditional semiconductor based digital architectures. Many recent advances in information processing have been enabled by the development of Integrated Microwave Photonics, Optical Neuromorphic Computing, and Quantum Photonics platforms. Our research utilizes experimental methods and Multiphysics simulations to explore interesting correlations between fundamental light-matter interactions and photonic device functionality in the Visible to midIR and THz regime. We are particularly interested in understanding how to use structurally driven anisotropy to modify or tune a material’s “effective” optical properties. In this talk, we will introduce phase change chalcogenides on nanostructured silicon (PCNS) as a novel optical metamaterial with an actively tunable effective permittivity and anisotropic thermal diffusivity which leads to intriguing, lower power, dynamic behavior. We will also show how PCNS can be used to modify the resonant behavior of THz metasurfaces by creating small perturbations in regions of strong optical mode confinement. In addition, we will explore hyperbolic optical media with extreme in-plane anisotropy which supports interesting polariton interactions such as spatial confinement and tunable resonant behavior. We will show how resonator geometry influences the optical behavior of mid-Infrared phonon-polaritons in highly anisotropic hyperbolic media which led to new fundamental physics and functionality of hyperbolic metamaterials for photonics applications.
Bio: Dr. Eric Seabron has been an assistant professor in the Electrical Engineering Department at Howard University since 2021. He received his PhD in Material Science and Engineering from the University of Illinois – Urbana Champaign in 2017. His graduate research focused on the growth and nanoscale metrology of Carbon Nanotubes and Gallium Arsenide Nanowires. After graduating, he spent 3 years as a microelectronics engineer developing semiconductor fabrication processes at Northrop Grumman Corporation. In 2020, he was awarded the NRC postdoctoral fellowship to conduct experimental research on optical metamaterials at the Naval Research Laboratory in Washington DC. His current research interest includes fundamental light-matter-heat physics in structured media, reconfigurable microwave and THz devices, dynamic infrared photonics and optoelectronics, memristive functionality for neuromorphic computing.",https://events.umich.edu/event/106573,"West Hall",335,"West Hall",,"Physics
Science","Interdisciplinary QC/CM Seminars
Department of Physics"
107134-21815401,"2023-04-13 16:00:00","2023-04-13 17:00:00","Special Interdisciplinary QC/CM Seminar | The Dark Energy of Quantum Materials","Laura H. Greene (National MagLab and Florida State University)","Workshop / Seminar","The many correlated electron problems remain largely unsolved after decades; with one stunning success being BCS electron-phonon mediated conventional superconductivity. The Cooper pairing mechanisms of the dozens of families of unconventional superconductors, including the high-Tc cuprate, iron based, and heavy fermion superconductors remain elusive and quite varied. But some of their fundamental characteristics are strikingly similar, including their ubiquitous phase diagram, with intriguing, correlated electron (non-Fermi liquid) phases that break the symmetry of their underlying lattice at temperatures well above T_c. These correlated phases remain among the greatest unsolved problems in physics; and I will present an analogy stressing that. I will start with an overview of the US National MagLab and finish a glimpse of some of my own recent work possibly identifying a possible new pairing mechanism in a heavy-fermion superconductor.",https://events.umich.edu/event/107134,"West Hall",335,"West Hall",,"Physics
Science","Interdisciplinary QC/CM Seminars
Department of Physics"
105013-21810582,"2023-04-14 10:00:00","2023-04-14 11:00:00","Statistics Department Seminar Series: Nancy Zhang, Professor, Department of Statistics and Data Science, The Wharton School, University of Pennsylvania",,"Workshop / Seminar","""Tumor subclone detection and niche differential expression analysis on spatial transcriptomics data""
Single cells influence, and are shaped by, their local tissue microenvironment. High resolution technologies for in situ profiling of gene expression at the transcriptome scale are rapidly maturing, enabling the detailed interrogation of the distribution of cell types in situ as well as the elucidation of local signaling patterns between cell types. In this talk, I will describe new computational methods for the analysis of spatial transcriptomics data, and illustrate their application to the study of cancer. First, I will focus on the detection of somatic copy number aberrations from spatial transcriptomic and single cell data, and the use of somatic copy numbers in the differentiation of malignant from normal tissue and the characterization of tumor subclonal evolution. Next, I will discuss niche-differential expression (niche-DE) analysis. Niche-DE identifies cell-type specific niche-associated genes, defined as genes whose single cell expression is significantly up- or down-regulated in the context of specific spatial niches. Although niche-DE is conceptually defined on the single-cell level, we show that niche-DE genes can be recovered from lower resolution spatial transcriptomic (ST) data where each observation is a spot containing a mixture of cell types. We apply the methods to the study of the tumor microenvironment on spatial transcriptomic data from multiple cancer types.",https://events.umich.edu/event/105013,"West Hall",411,"West Hall",,Physics,"Department of Statistics
Department of Statistics Seminar Series"
105607-21812261,"2023-04-17 15:00:00","2023-04-17 16:30:00","The Michigan Anthropology Colloquia Series","""A Behavioral Ecology View on the Gender-Health Paradox"" by Siobhán M. Mattison","Lecture / Discussion","The Department of Anthropology proudly presents
The Michigan Anthropology Colloquia series
""A Behavioral Ecology View on the Gender-Health Paradox""
By Siobhán M. Mattison, associate professor of evolutionary anthropology, University of New Mexico
In-Person: 3PM, 411 West Hall
Virtual: https://umich.zoom.us/j/92496167134
Why is it that women outlive men yet experience higher morbidity along the way? Public health perspectives have provided important insights on the various factors contributing to the so-called gender-health paradox, but lack a unifying underlying framework to tie different predictors together. In this talk, I describe how behavioral ecology can help to unite disparate findings and explain if and when these trends might be reversed. ""Gender reversals"" in health among matrilineal and patrilineal Mosuo of China illustrate how underlying variation in socio-ecologies impacts gender differences in health, with important implications for interventions designed to mitigate disparities.
ABOUT THE SPEAKER
Siobhán M. Mattison is an associate professor of evolutionary anthropology at the University of New Mexico and a rotator at the National Science Foundation. Her research focuses on explaining health and welfare in light of variation in human kinship and social structure norms. She conducts fieldwork with the Mosuo (Na) of Southwest China and among the Melanesian Ni-Vanuatu. She received her doctoral degree in biocultural anthropology from the University of Washington and trained as a postdoctoral fellow in anthropology and demography at Stanford University.",https://events.umich.edu/event/105607,"West Hall",411,"West Hall",,"AEM Featured
Anthropology
Biosciences
Ecology And Evolutionary Biology
Psychology","Department of Anthropology"
107615-21816277,"2023-04-18 17:00:00","2023-04-18 18:00:00","Local wellposedness of water wave equations with angled crests on the interface",Jasper,"Workshop / Seminar","A class of water wave problems concerns the dynamics of the free interface separating an inviscid, incompressible and irrotational fluid from the vacuum under the influence of gravity. In this talk, we survey some results on wellposedness of these water wave equations, and introduce a relatively recent approach that allows us to deal with interfaces that have angled crests.",https://events.umich.edu/event/107615,"West Hall",335,"West Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics"
107388-21815939,"2023-04-21 10:00:00","2023-04-21 11:00:00","Statistics Department Seminar Series: Purnamrita Sarkar, Associate Professor, Department of Statistics, The University of Texas at Austin",,"Workshop / Seminar","""Some new results for streaming principal component analysis""
Streaming PCA, also known as Oja's algorithm, with roots going back to 1949, has attracted much attention in Statistics and Computer Science in the last decade. In this talk, I will discuss two of our works that address uncertainty estimation and data dependence, which have been relatively underexplored in the past.
First, I will talk about the problem of quantifying uncertainty for the estimation error of the leading eigenvector using Oja's algorithm for streaming PCA, where the data are generated IID from some unknown distribution. Combining classical tools from the U-statistics literature with recent results on high-dimensional central limit theorems for quadratic forms of random vectors and concentration of matrix products, we establish a distributional approximation result for the error between the population eigenvector and the output of Oja's algorithm. We also propose an online multiplier bootstrap algorithm and establish conditions under which the bootstrap distribution is close to the corresponding sampling distribution with high probability.
Our second work looks at dependent data streams. While streaming PCA is typically analyzed under the IID data model, in many applications like distributed optimization, data points are sampled from a Markov chain and therefore are dependent. I will show how the data dependence leads to difficulties in the theoretical analysis and present our finite sample convergence guarantees under standard assumptions on the underlying Markov chain.",https://events.umich.edu/event/107388,"West Hall",340,"West Hall",,Physics,"Department of Statistics
Department of Statistics Seminar Series"
107653-21816322,"2023-04-24 16:00:00","2023-04-24 17:00:00","HEP-Astro Seminar | Pushing the limits of PDFs with LHCb","Thomas Boettcher (University of Cincinnati)","Workshop / Seminar","Understanding data from hadron colliders such as RHIC and the LHC requires understanding the structure of the colliding hadrons. At the same time, studying the structure of nucleons allows us to probe the strong interactions of confined quarks and gluons. The momentum distributions of quarks and gluons in nucleons are encoded in parton distribution functions (PDFs). Extracting PDFs from experimental data relies on several assumptions, and finding where these assumptions break down can reveal new insights about QCD in poorly understood regimes. In this talk, I will present measurements by the LHCb collaboration that challenge some of these assumptions by probing the structure of nucleons in extreme conditions. I will present a study of Z-boson production in association with charm quarks that could point to a non-perturbative contribution to the charm quark PDF. I will also present studies of particle production in proton-lead collisions and discuss their implications for nuclear modifications of PDFs and QCD at high gluon densities.",https://events.umich.edu/event/107653,"West Hall",340,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
107683-21816362,"2023-05-01 09:30:00","2023-05-01 17:00:00","The 8th LCTP Spring Symposium",,"Conference / Symposium","Indirect Searches for Dark Matter",https://events.umich.edu/event/107683,"West Hall",340,"West Hall",,"physics
science","Leinweber Center for Theoretical Physics
Department of Physics
Leinweber Center for Theoretical Physics Workshops and Conferences"
107683-21816363,"2023-05-02 09:30:00","2023-05-02 17:00:00","The 8th LCTP Spring Symposium",,"Conference / Symposium","Indirect Searches for Dark Matter",https://events.umich.edu/event/107683,"West Hall",340,"West Hall",,"physics
science","Leinweber Center for Theoretical Physics
Department of Physics
Leinweber Center for Theoretical Physics Workshops and Conferences"
107683-21816364,"2023-05-03 09:00:00","2023-05-03 12:30:00","The 8th LCTP Spring Symposium",,"Conference / Symposium","Indirect Searches for Dark Matter",https://events.umich.edu/event/107683,"West Hall",340,"West Hall",,"physics
science","Leinweber Center for Theoretical Physics
Department of Physics
Leinweber Center for Theoretical Physics Workshops and Conferences"
107259-21815687,"2023-05-03 15:00:00","2023-05-03 16:00:00","Interdisciplinary QC-CM Seminar | Design Principles for Sustainable Chemistry: A Theoretical and Machine Learning Approach","Seonah Kim (Colorado State University, Department of Chemistry)","Workshop / Seminar","The overarching goal of our group is to develop new methods to extract sustainable fuels, polymers and chemicals from plants. Our approach has been to develop and apply computational tools to both biological and chemical conversion processes as part of an iterative ‘model-validate-predict’ design process for de novo catalysts.
With its high carbon and hydrogen content, lignocellulosic biomass presents an alternative to petroleum as a nearly carbon-neutral precursor to upgraded liquid fuels. I will present some representative results in designing new catalysts for biological and chemocatalytic processes of biomass.
Our group has introduced a “Fuel property first” design approach to reduce emissions and increase performance for biofuel candidates. Traditional approaches for developing these mechanistic models require many years for each new molecule, a pace that is poorly suited to the large-scale search for new bioderived blendstocks. We have developed chemistry and physics informed graph neural networks models to predict few fuel properties including yield sooting index (YSI), cetane number (CN), critical temperature (T_c), and heat of vaporization (HoV). These properties are key factors in determining fuel performance, emissions, and safety, and can vary substantially between bioblendstock candidates under consideration. The model and methodology used in this work can be applied to other fuel properties, leading to rational principles for designing high-performance fuels.",https://events.umich.edu/event/107259,"West Hall",335,"West Hall",,"Physics
Science","Interdisciplinary QC/CM Seminars
Department of Physics"
107233-21819157,"2023-06-01 13:00:00","2023-06-01 14:30:00","MIDAS Seminar: Alfred Hero - NSF Priorities and Opportunities for Data Science and AI",,"Lecture / Discussion","Speaker: Dr. Alfred Hero, Program Director in the NSF CISE Directorate, and the John H. Holland Distinguished University Professor of Electrical Engineering and Computer Science and R. Jamison and Betty Williams Professor of Engineering, University of Michigan
Date: June 1, 2023
Time: 1:00-2:30 PM
Location: West Hall 340
Register here: https://myumi.ch/y2jAW
As data science and AI have continued to permeate society, the National Science Foundation (NSF) has introduced new programs in the foundations of the data sciences and its applications to scientific problems. This talk will provide an overview of some of NSF's activities and opportunities in data science and related fields.
Dr. Alfred Hero is the John H. Holland Distinguished University Professor of Electrical Engineering and Computer Science and the R. Jamison and Betty Williams Professor of Engineering at the University of Michigan, Ann Arbor. He is currently on leave from the University of Michigan as a Program Director in the CISE Directorate at the National Science Foundation. He is a Fellow of the Institute of Electrical and Electronics Engineers (IEEE) and the Society for Industrial and Applied Mathematics (SIAM). He is a recipient of the Fourier Award in Signal Processing from the IEEE.
Thirty minutes of networking with attendees following the presentation. Light refreshments provided.
Live-streaming is not available for this event. Post-event recording available upon request.",https://events.umich.edu/event/107233,"West Hall",340,"West Hall",,"data
Data Science
Information and Technology
Midas
Research
seminar
Technology","Michigan Institute for Data Science"
108475-21819631,"2023-06-08 13:00:00","2023-06-08 14:00:00","Physics Graduate Student Symposium (PGSS) | Assumptions of Physics","Christine Aidala (U-M Physics)","Workshop / Seminar","The Assumptions of Physics project seeks to find a minimal set of physical assumptions from which the basic laws of physics can be rigorously rederived. It consists of two complementary approaches. The first, Reverse Physics, analyzes known theories to identify those physical principles and assumptions that can be taken as their conceptual foundation. The second, Physical Mathematics, seeks to identify and construct mathematical structures that can be rigorously justified from physical requirements and are therefore physically significant. Results from both approaches will be presented, as well as future plans and opportunities to contribute.
More dates and speakers can be found on the PGSS website: https://pgss.physics.lsa.umich.edu/speakers/2023",https://events.umich.edu/event/108475,"West Hall",335,"West Hall",,"Graduate Students","Department of Physics"
108375-21819443,"2023-06-12 11:00:00","2023-06-12 12:00:00","Special Interdisciplinary QC/CM Seminars | Dynamical Fractal and Anomalous Noise in a Clean Magnetic Crystal","Roderich Moessner (Max Planck Institute for Complex Systems)","Workshop / Seminar","Fractals -- objects with non-integer dimensions -- occur in manifold settings and length scales in nature, ranging from snowflakes and lightning strikes to natural coastlines. Much effort has been expended to generate fractals for use in many-body physics. Here, we identify an emergent dynamical fractal in a disorder-free, stoichiometric three-dimensional magnetic crystal in thermodynamic equilibrium. The phenomenon is born from constraints on the dynamics of the magnetic monopole excitations in spin ice, which restrict them to move on the fractal. This observation explains the anomalous exponent found in magnetic noise experiments in the spin ice compound Dy2Ti2O7, and it resolves a long standing puzzle about its rapidly diverging relaxation time. The capacity of spin ice to exhibit such striking phenomena holds promise of further surprising discoveries in the cooperative dynamics of even simple topological many-body systems.
Science 378, 1218 (2022)",https://events.umich.edu/event/108375,"West Hall",335,"West Hall",,"Physics
Science","Interdisciplinary QC/CM Seminars
Department of Physics"
108476-21819632,"2023-06-15 13:00:00","2023-06-15 14:00:00","Physics Graduate Student Symposium (PGSS) | Bringing Hot and Cold Atoms from Academic Labs to Real-World Applications","Alisher Duspayev, Sixth Year (U-M Physics)","Workshop / Seminar","Using various properties of atoms as a basis for novel technologies has attracted a lot of interest in recent years. Such properties include large electric-dipole moments, shifts of quantized energy levels in external fields, ultranarrow linewidths of transitions between quantum states, etc. Prominent examples of already-existing atom-based technologies include room-temperature Rydberg-atom-based field sensors, portable atomic clocks and quantum simulators based on cold atoms or trapped ions. In this talk, I will overview the concurrent efforts to realize novel atom-based technologies and discuss the relevant physics behind these ideas. In the second part, I will focus on what is being done in this direction by our group on the sub-basement level of the Physics Department at UMich. In particular, I will discuss the recent demonstration of how Rydberg atoms can be used to monitor electric fields within cold-ion sources. The talk will be concluded with a brief outlook for the ongoing effort to realize a novel type of atom interferometer for inertial sensing.",https://events.umich.edu/event/108476,"West Hall",335,"West Hall",,"Graduate Students","Department of Physics"
108602-21820193,"2023-06-19 12:00:00","2023-06-19 13:00:00","Special Quantitative Biology Seminar | From Interfacial Tubulation in Alcanivorax Borkumensis Biofilms to Buckling of Liquid-Crystal Membranes","Carles Blanch Mercader (Institut Curie, Paris)","Workshop / Seminar","Anisotropic cells can exhibit long-range orientational order and topological defects, which often influence their dynamics during shape formation. In the first part of this talk, I will present conditions for a morphological transition between a spherical and a dendritic phase in Alcanivorax borkumensis biofilm-covered oil microdroplets. Using phase-field approaches, we studied how tubulation dynamics on 2d liquid-liquid interfaces are modified by bacteria proliferation with an homeostatic state. Experimental observations demonstrate preferential interfacial tubulation at topological defects, with bacterial assemblies on the tubes exhibiting long-range nematic order. The second part of this talk focuses on the impact of explicit order-curvature couplings on the buckling of liquid-crystal membranes at integer topological defects. We identified conditions that lead to the instability of flat membranes, highlighting the profound influence of order-curvature coupling. These results show how bacteria biofilms can utilize topological defects to facilitate membrane deformation and enhance oil access.",https://events.umich.edu/event/108602,"West Hall",335,"West Hall",,"Physics
Science","Quantitative Biology Seminars
Department of Physics"
108477-21819633,"2023-06-22 13:00:00","2023-06-22 14:00:00","Physics Graduate Student Symposium (PGSS) | Exploring Biophysics using the toolbox of Nonequilibrium Thermodynamics","Gabriela Fernandes Martins, Fifth Year (U-M Physics)","Workshop / Seminar","The development of Thermodynamics was a stepping-stone to understanding the properties of complex systems, allowing to constrain which types of processes are physically realizable. However, classical Thermodynamics does not describe nonequilibrium systems, which represent a large range of phenomena observed in nature, including life itself. Examples range from the transport of cargo by molecular motors and gene transcription, to bacterial chemotaxis and beyond. Achieving a unified theoretical description of all such processes is challenging, and in the last years, physicists have teamed with biologists to apply the tools of Nonequilibrium Thermodynamics to study such phenomena. In this talk, I will provide a gentle introduction to Stochastic Thermodynamics, a field of Nonequilibrium thermodynamics. Special focus will be given to Markov-jump processes and its direct applications to describing biophysical systems. I will finish by showing how this toolbox can be used to derive fundamental operational limits of a general biochemical motif consisting of a ligand binding to a receptor.",https://events.umich.edu/event/108477,"West Hall",335,"West Hall",,"Graduate Students","Department of Physics"
108992-21820696,"2023-06-27 10:30:00","2023-06-27 11:30:00","On the Benefits of Multitask Learning: A Perspective Based on Task Diversity","Ziping Xu",Other,"Abstract:
Multitask learning (MTL) has achieved remarkable success in numerous domains, such as healthcare, computer vision, and natural language processing, by leveraging the relatedness across tasks. However, current theories of multitask learning fall short in explaining the success of some phenomena commonly observed in practice. For instance, many empirical studies have shown that having a diverse set of tasks improves both training and testing performance. This thesis aims at providing new theoretical insights into the significance of task diversity in two major learning settings: Supervised Learning and Reinforcement Learning. For supervised MTL, we focus on studying a popular learning paradigm known as multitask representation learning and provide a theoretical foundation that establishes diversity as a crucial condition for achieving good generalization performance. In the setting where tasks can be
adaptively chosen, we propose an online learning algorithm that effectively achieves diversity with low regret. I then expand the discussion to Reinforcement Learning (RL), which involves making sequential decisions to optimize long-term rewards. Previous exploration designs in RL were either computationally intractable or lacked formal guarantees. We show that, in addition to the generalization benefits demonstrated in supervised learning, multitask reinforcement learning with a diverse set of tasks enables sample-efficient myopic exploration. This is surprising because myopic exploration is provably sample efficient in the worst case even for a single task.",https://events.umich.edu/event/108992,"West Hall",438,"West Hall",,Dissertation,"Department of Statistics Dissertation Defenses"
108857-21820488,"2023-06-27 15:00:00","2023-06-27 16:00:00","Special Department Seminar: Controlling Complex Quantum Noise with Many-Time Physics","Prof. Kavan Modi (Centre for Quantum Technology and Monash University)","Workshop / Seminar","Please join us in 335 West Hall or via Zoom:
Meeting ID: 923 7994 3630
Passcode: 577482
Abstract: There are dozens of efforts, in academia, industry, and national labs, dedicated to building error-corrected quantum computers. Achieving this milestone will require understanding and controlling complex quantum noise, including non-Markovian noise. Such noise spans many qubits and many gates, leading to highly complex spatial-temporal quantum-correlated structures. Both describing and characterising such noise have been outstanding challenges, hindering the hopes of controlling this noise.
I will present recent theoretical breakthroughs to express all quantum non-Markovian phenomena in terms of a multi-time density matrix. In this picture, quantum processes possess complex temporal entanglement responsible for exotic dynamical phases, quantum chaos, computationally complex processes, and much more. The culmination of these effects leads to a new discipline that we call many-time physics in analogy to many-body physics.
An immediate application of many-time physics is a set of operational tools to characterise and control complex noise. In particular, I will report both the detailed features and coarse structures of noise in real quantum devices, including temporal entanglement. We then go on to tame this noise with high efficacy using active control, along with the characterisation information.
Biography: Since mid-2022, Kavan Modi has served as the founding Director of the Centre for Quantum Technology at Transport for New South Wales. Currently, he is on leave from Monash University, where he has been a member of the faculty at the School of Physics and Astronomy since 2014. Prior to this, he was a postdoctoral fellow at the Clarendon Lab, University of Oxford (2012-2013) and at the Centre for Quantum Technology, National University of Singapore (2009-2011). He received his Ph.D. under Prof. George Sudarshan at the University of Texas at Austin in 2008. His research, at Monash, focuses on understanding the structure of complex quantum processes so that they can be characterised and controlled in quantum computers. His research, at TfNSW, focuses on developing quantum algorithms to aid transport use cases. On the whole, his research builds meaningful bridges between fundamental physics and its applications in engineering and software development.",https://events.umich.edu/event/108857,"West Hall",335,"West Hall",,"Faculty
Free
Graduate Students
Physics","Department of Physics"
108478-21819634,"2023-06-29 13:00:00","2023-06-29 14:00:00","Physics Graduate Student Symposium (PGSS) | Solitons: An Unexpected Journey Through First-Year Graduate Level Physics","Matthew Mitchell, Fifth Year (U-M Physics)","Workshop / Seminar","Over the last half-century, there has been increased interest in many integrable nonlinear evolution equations, such as the Nonlinear Schrodinger, Sine-Gordon, Korteweg-de Vries, and Benjamin-Ono equations, due to their ubiquity in describing physical systems exhibiting weakly nonlinear and dispersive behavior along with the remarkable fact that all of these equations have the same qualitative solution method, generally known as an Inverse Scattering Transform. A peculiar phenomenon also shared by many of these equations has to do with a particular set of solutions known as solitons, which have a distinctly particle-like behavior: a spatially localized profile propagating at a fixed speed when alone, obeying a ""nonlinear superposition principle"" so many individual solitons can be present in a solution at once, and maintaining their individual identities after interacting. In order to demystify these peculiar solutions, we'll embark on a mathematical journey that will take us to some unexpected places. To survive, you'll need your wits about you, specifically, most of your knowledge from your first-year graduate physics courses. You have been warned!",https://events.umich.edu/event/108478,"West Hall",335,"West Hall",,"Graduate Students
Physics","Department of Physics"
108479-21819635,"2023-07-06 13:00:00","2023-07-06 14:00:00","Physics Graduate Student Symposium (PGSS) | Holographic Renormalization Group Flows Across Dimensions","Robert Saskowski, Fifth Year (U-M Physics)","Workshop / Seminar","Renormalization group (RG) flows are commonly used in quantum field theory to describe the changes in degrees of freedom as we ""flow"" from very high to very low energies. In particular, there have been a number of proofs of the irreversibility of RG flows in various dimensions, i.e., the statement that the number of high-energy degrees of freedom is larger than the number of low-energy degrees of freedom. In this talk, I will discuss RG flows across dimensions, which one can think of as probing compact extra dimensions. We will do so using the powerful tool of holography, which allows us to recast this field theoretic problem as a geometric flow in anti-de Sitter space.",https://events.umich.edu/event/108479,"West Hall",335,"West Hall",,,"Department of Physics"
108480-21819636,"2023-07-13 13:00:00","2023-07-13 14:00:00","Physics Graduate Student Symposium (PGSS) | All-Infrared Electromagnetically Induced Transparency with Rydberg Atoms","Ryan Cardman, Sixth Year (U-M Physics)","Workshop / Seminar",TBA,https://events.umich.edu/event/108480,"West Hall",335,"West Hall",,"Graduate Students","Department of Physics"
109238-21821295,"2023-07-20 13:00:00","2023-07-20 14:00:00","Physics Graduate Student Symposium (PGSS) | A Short Guide to Gravitational Wave Cosmology","Isaac McMahon (Department of Physics)","Workshop / Seminar","Gravitational waves have emerged as a new method for measuring the Hubble constant. With recent upgrades to active detectors and future instruments in the works, this new measurement should soon rival the canonical late and early universe measurements in precision and introduce another facet to the Hubble tension. In this talk, I'll walk through the current process of how gravitational wave detection and observational astronomy interlace to make multimessenger cosmology. I'll talk about how gravitational waves are used to infer properties of compact object collisions, how telescopes all over the world are employed to search for a visual signal from the collisions, and then how these signals are combined to measure cosmological parameters.",https://events.umich.edu/event/109238,"West Hall",335,"West Hall",,Free,"Department of Physics"
109335-21821482,"2023-07-24 09:00:00","2023-07-24 12:00:00","Learning Structure in High-Dimensional Data with Applications to Neuroimaging","Daniel Kessler","Lecture / Discussion","Abstract:
The scale of modern datasets, with more and more variables measured on more and more observations, presents many statistical challenges, but also opportunities to discover and exploit the rich structure that is often present in the data. In neuroimaging studies, multiple kinds of brain imaging are conducted on the same participant, with each modality of imaging having its own further structure, and many associated phenotypic measurements taken on the participants. Understanding the complicated and noisy underlying relationships between all of these measurements holds promise for scientific and treatment breakthroughs in the long term, and requires sophisticated methods designed to uncover this structure. This thesis presents three projects on learning structure in high-dimensional datasets motivated by applications in neuroimaging.
The first project considers the setting where many networks are observed on a common node set: each observation comprises edge weights, covariates observed at each node, and a response. In our neuroimaging application, the edge weights correspond to functional connectivity between brain regions, node covariates encode task activations at each brain region, and performance on a behavioral task is the response. The goal is to use the edge weights and node covariates to predict the response and to identify a parsimonious and interpretable set of predictive features. We propose an approach that uses feature groups defined according to a community structure believed to exist in the network (naturally occurring in neuroimaging applications). We propose two schemes for forming feature groups where each group incorporates both edge weights and node covariates, and derive optimization algorithms for both using an overlapping group LASSO penalty. Empirical results on synthetic data show that our method, relative to competing approaches, has similar or improved prediction error along with superior support recovery, enabling a more interpretable and potentially a more accurate understanding of the underlying process. We also apply the method to neuroimaging data.
The second project focuses on inference for structure learned using Canonical Correlation Analysis (CCA). CCA is a method for analyzing a sample of pairs of random vectors; it learns a sequence of paired linear transformations of the original variables that are maximally correlated within pairs while uncorrelated across pairs. CCA outputs both canonical correlations as well as the canonical directions which define the transformations. While inference for canonical correlations is well developed, conducting inference for canonical directions is more challenging and not well-studied, but is key to interpretability. We propose a computational bootstrap method for inference on CCA direction (kombootcca). We conduct thorough simulation studies that range from simple and well-controlled to complex but realistic and validate the statistical properties of kombootcca while comparing it to several competitors. We also apply the kombootcca method to a brain imaging dataset and discover linked patterns in brain connectivity and behavioral scores.
The third project proposes a new method for matrix CCA (matcca), which works with pairs of random matrices rather than pairs of random vectors, motivated by a neuroimaging application where the brain imaging data takes the form of a high-dimensional covariance matrix. Our matcca method uses a nuclear norm penalty that encourages the canonical directions associated with the matrix-variate data to have low rank structure when arranged into a matrix. Results from both synthetic and neuroimaging data show that matcca is very effective at recovering low rank signals even in noisy cases with few observations.",https://events.umich.edu/event/109335,"West Hall",411,"West Hall",,Dissertation,"Department of Statistics Dissertation Defenses"
108482-21819638,"2023-07-27 13:00:00","2023-07-27 14:00:00","Physics Graduate Student Symposium (PGSS) | Networks, Information Theory, and Rankings","Maximilian Jerdee, Fourth Year (U-M Physics)","Workshop / Seminar",TBA,https://events.umich.edu/event/108482,"West Hall",340,"West Hall",,"Graduate Students
Physics","Department of Physics"
108481-21819637,"2023-08-03 13:00:00","2023-08-03 14:00:00","Physics Graduate Student Symposium (PGSS) | Ultrafast Time-Resolved Spectroscopy Using Optical and X-ray Probes Elucidates the Structural and Electronic Evolution of Photoexcited Coenzyme B12","Taylor McClain, Fifth Year (U-M Biophysics)","Workshop / Seminar","Coenzyme B12, also known as adenosylcobalamin (AdoCbl), is an important enzymatic cofactor in prokaryotic and eukaryotic species. This molecule consists of a central cobalt coordinated equatorially to a corrin ring ligand, with a lower axial dimethylbenzimidazole α-ligand and an upper axial deoxyadenosyl β-ligand. AdoCbl’s ground state reactivity has been studied in detail, but it was only recently that its role as chromophore in the bacterial photoreceptor protein CarH showed a biological usage of the molecule’s inherent light-sensitivity. The light-induced response of AdoCbl can be characterized using time-resolved spectroscopies. Presently, our group has performed studies with transient absorption (TA) UV-Vis spectroscopy, X-ray absorption spectroscopy, and X-ray emission spectroscopy. TA spectroscopy provides electronic information about the valence orbitals of the system. The X-ray spectroscopies are element-specific probes of the electronic and atomic structure around the central cobalt atom of the AdoCbl. These studies reveal a distinct solvent-dependence of AdoCbl photochemistry as well as a dynamic dance of structural distortions immediately following light excitation. Time-dependent density functional theory (TD-DFT) and finite difference method (FDM) calculations are used to simulate the X-ray absorption and emission spectra. This information is crucial for understanding the CarH protein more deeply as well as bringing cobalamin-based light-mediated drug delivery and optogenetic applications closer to reality.",https://events.umich.edu/event/108481,"West Hall",340,"West Hall",,"Graduate Students
Physics","Department of Physics"
109797-21822912,"2023-08-10 10:00:00","2023-08-10 14:00:00","Physics REU Symposium","Various Student Speakers","Conference / Symposium","Summer undergraduate research students will present their research results in a series of short talks at the REU Symposium. All are welcome to attend. For additional information, contact Jim Liu (jimliu@umich.edu).",https://events.umich.edu/event/109797,"West Hall",340,"West Hall",,"Faculty
Free
Graduate Students
Physics
Undergraduate Students","Department of Physics"
108484-21819640,"2023-08-17 13:00:00","2023-08-17 14:00:00","Physics Graduate Student Symposium (PGSS) | Higher Order Threshold Dynamics Schemes for Motion by Mean Curvature","Jiajia Guo, Fourth Year (U-M Mathematics)","Workshop / Seminar","Threshold dynamics is well known as a popular algorithm for simulating the motion of interfaces; nowadays, it's broadly used in image segmentation and solid dewetting. The original version of the algorithm, which is only first-order accurate in time in the two-phase setting, was proposed by Merriman, Bence, and Osher in 1992. Since then, many extensions of the algorithm have been given, for instance, to multiphase mean curvature motion, where it has proven particularly useful and flexible. There have also been high-order accurate versions of the algorithm proposed in several previous studies. Our goal is to take a step toward providing more accurate versions of threshold dynamics with nice properties, for example, monotonicity, which respects the comparison principle of the exact evolution. We'll also introduce our recent finding: the connection between threshold dynamics and the median filter, which is an elegant, monotone discretization of the level set formulation of motion by mean curvature. This results in a new level set method for multiphase mean curvature motion that allows locating the interface via interpolation and enforces the correct junction condition at the free boundaries, at the generality demanded by applications.",https://events.umich.edu/event/108484,"West Hall",340,"West Hall",,"Graduate Students
Physics","Department of Physics"
108485-21819641,"2023-08-24 13:00:00","2023-08-24 14:00:00","Physics Graduate Student Symposium (PGSS) | Using Single-Molecule Microscopy to Probe Actin-Membrane Interactions in Live Cells","Adam Decker, Third Year (U-M Biophysics)","Workshop / Seminar",TBA,https://events.umich.edu/event/108485,"West Hall",335,"West Hall",,"Graduate Students
Physics","Department of Physics"
110807-21825556,"2023-08-29 16:00:00","2023-08-29 17:00:00","CM-AMO Seminar | Entanglement-Enhanced Sensing and Data Processing","Zheshen Zhang (U-M Electrical Engineering and Computer Science)","Workshop / Seminar","The 20th century has witnessed the rise of quantum mechanics and its fueled scientific and technological revolution. The humankind is now on the verge of a second quantum revolution sparked by quantum information science and engineering (QISE). Entanglement as a quintessential quantum resource lies at the heart of QISE, giving rise to a plethora of quantum-enabled or enhanced capabilities that shift the landscape of communication, sensing, and computing. In this talk, I will present our recent experimental advances in entanglement-enhanced sensing and data processing. I will first describe entangled sensor networks for precise radiofrequency and optomechanical sensing beyond the standard quantum limit. Building on entangled sensors, I will introduce quantum-enhanced machine learning for data classification at a physical layer. Next, I will discuss a major endeavor to foster the transition from basic quantum research to near-term, widely impactful real-world quantum technologies: the construction of a quantum network testbed as a distributed infrastructure to advance convergent QISE research and education.
Biographical sketch: Dr. Zheshen Zhang is an Associate Professor of Electrical Engineering and Computer Science at University of Michigan–Ann Arbor. Prior to joining University of Michigan, Dr. Zhang was an Assistant Professor at University of Arizona from 2017 to 2022, a Research Scientist, and a Postdoctoral Associate both at MIT from 2012 to 2017. Dr. Zhang received his PhD degree in Electrical and Computer Engineering from Georgia Tech. Dr. Zhang's research encompasses a broad spectrum of quantum networks, quantum communications, quantum sensing, and quantum computing. His team harnesses unique quantum resources such as entanglement to develop quantum sensors surpassing the classical measurement limits, quantum communication systems with enhanced security and capacity, quantum networks for long-range entanglement distribution, and quantum processors capable of tackling problems intractable on classical computers. His work was recognized by an NSF CAREER Award in 2022. Dr. Zhang currently serves on the Editorial Board of Communications Physics of Nature Portfolio and Progress in Quantum Electronics of Elsevier.",https://events.umich.edu/event/110807,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
110508-21824998,"2023-08-30 15:00:00","2023-08-30 16:00:00","Special Physics Colloquium | State of Department Address","David Gerdes, Department of Physics Chair",Presentation,"David Gerdes, Department of Physics Chair, will present information about the physics department's current environment. Students, staff, and faculty are encouraged to attend.
This event will be an in-person event; however, it will also be recorded on Lecture Capture to view at a later date.
The link for the lecture capture recording will be available here after the presentation has taken place. The presentation will not be live-streamed.
A reception will be hosted before the lecture, starting at 2:30 p.m. in the Don Meyer Commons.",https://events.umich.edu/event/110508,"West Hall",340,"West Hall",,"AEM Featured
Faculty
Graduate Students
Physics
Staff
Undergraduate Students","Department Colloquia
Department of Physics
Applied Physics
Undergrad Physics Events"
110957-21825915,"2023-09-05 16:00:00","2023-09-05 17:00:00","CM-AMO Seminar | What Can Batteries Teach Us About Microelectronics (And Vice Versa)?","Yiyang Li (U-M Materials Science and Engineering)","Workshop / Seminar","Batteries and advanced microelectronic devices are two of the most important technologies today. In this talk, I will share the common materials physics concepts shared among these two critical technologies. First, I will present our research on resistive random-access memory, a type of emerging memory cell that stores information using ions. Our work shows how composition phase separation among these ions enables such memory cells to retain information over time. Next, I will present our research on the use of microfabricated electrodes to measure lithium reaction and diffusion rates in individual Li-ion battery particles. Using these electrodes, we show that the microcracks in polycrystalline battery particles are necessary for the rapid charge and discharge of battery particles. Our work shows the crucial role of ion transport among these two important technologies.
Biography: Yiyang Li is an Assistant Professor of Materials Science and Engineering at the University of Michigan. He received his BS in Electrical Engineering at Olin College, a PhD in Materials Science and Engineering at Stanford University, and was a Harry Truman Fellow at Sandia National Laboratories. Prof. Li conducts research combining electrochemistry, microelectronics, and data science. He received the Intel Rising Star Faculty Award in 2022.",https://events.umich.edu/event/110957,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
111372-21826911,"2023-09-06 16:10:00","2023-09-06 17:00:00","Department of Astronomy 2023-2024 DEI Series Presents:","Dr. Mark Voit, Professor, Michigan State University","Lecture / Discussion","""DEI Conversation: Reflections on Inclusion""
A few years ago, I added a DEI feature called Reflections on Inclusion to both my introductory astronomy courses and the Cosmic Perspective textbook series I co-author. It's a collection of discussion prompts that encourage students to reflect on a wide range of issues related to inclusion in the field of astronomy. We will talk about the goals that guided the development of those prompts, my experiences with using them, and the ones that have led to the most engagement and thoughtfulness.
https://gmvoit.org/",https://events.umich.edu/event/111372,"West Hall",411,"West Hall",,astronomy,"Department of Astronomy
Michigan Institute for Research in Astrophysics"
111355-21826900,"2023-09-07 15:30:00","2023-09-07 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Mark Voit, Professor, Michigan State University","Lecture / Discussion","“Black Hole Masses in Massive Halos”
Whether or not the mass of a supermassive black hole (MBH) is causally linked to the mass of the halo around it (Mhalo) has been hotly debated for at least two decades. I will present evidence supporting a direct proportionality between MBH and the binding energy of the halo’s baryons that extends from Milky Way scales up to at least Mhalo ~ 10^14 MSun. That relationship is consistent with models of black-hole feedback that rely on cumulative kinetic energy injection to quench star formation by lifting the halo’s baryons. I will also show why some cosmological simulations do not reproduce the observed MBH-Mhalo relationship, even though baryon lifting through cumulative kinetic energy injection appears to be what quenches star formation in those simulations.
https://gmvoit.org/",https://events.umich.edu/event/111355,"West Hall",411,"West Hall",,colloquium,"Department of Astronomy
Michigan Institute for Research in Astrophysics"
109422-21822010,"2023-09-08 10:00:00","2023-09-08 11:00:00","Statistics Department Seminar Series: Jonathan Terhorst, Assistant Professor, Department of Statistics, University of Michigan","""Identifiability and inference of phylogenetic birth-death models""","Workshop / Seminar","Abstract: The phylogenetic birth-death model is widely used to study evolutionary processes like speciation and extinction, as well as the spread of pathogens. In this talk, I present some new theoretical and applied results concerning this model. Our first contribution is a scalable variational Bayesian method for inferring birth and death rates from very large quantities of serially-sampled genetic data. Our method produces results that are comparable to, or better than, existing MCMC-based approaches while being several orders of magnitude faster. We study the utility of our method for inferring present and historical epidemiological parameters for the COVID-19 pandemic. Our second contribution is theoretical, and consists of proving that the models we are inferring in the first part of the talk are in fact statistically identifiable. This result contrasts with (though does not contradict) recent nonidentifability theorems for phylogenetic birth-death models that have received significant attention. Finally, I will discuss some complementary hardness-of-estimation results which establish that, even in identifiable model classes, obtaining reliable inferences from finite amounts of data may be extremely challenging.
This is joint work with Brandon Legried and Caleb Ki.
https://jthlab.github.io/",https://events.umich.edu/event/109422,"West Hall",340,"West Hall",,seminar,"Department of Statistics Graduate Seminar Series
Department of Statistics
Department of Statistics Seminar Series"
110959-21825917,"2023-09-08 15:00:00","2023-09-08 16:00:00","HET Seminar | Nuclear Reactors, Nuclear Weapons, Neutrinos and Nonproliferation","James Wells (UM)","Lecture / Discussion","This talk has two goals. One is to introduce some of the technical issues associated with nuclear reactors and concerns of proliferation of fissile materials that can be used to construct a nuclear weapon. Examples are discussed, including reactor fuel issues and possible neutrino monitoring of nuclear reactors. The second goal, which is connected to the first, is to describe the current landscape in the dangerous resurgence of nuclear weapons, most especially in North Korea. Emphasis will be on science and technology's role in creating the threats and possibly mitigating them.",https://events.umich.edu/event/110959,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics
Science
Winter 2019","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
111632-21827345,"2023-09-11 15:00:00","2023-09-11 16:00:00","HEP-Astro Seminar | The Phantom Menace: Modified Gravity as an Alternative to the Planet Nine Hypothesis","Harsh Mathur (Case Western Reserve University)","Workshop / Seminar","We study the dynamics of outer solar system bodies under the influence of the modified gravity theory MOND. We find that tidal forces due to the Galaxy (which are much stronger in MOND than in Newtonian gravity) tend to align the major axes of the orbits of outer Kuiper belt objects with the direction towards the center of the galaxy. Such an alignment is seen in the orbits of the handful of outer Kuiper belt objects that are known at present. The observed alignment has previously led to the Planet Nine hypothesis: that there is a large undiscovered planet in the outer solar system. It is expected that in the near future surveys dedicated to the outer solar system as well as Dark Energy Survey, the Vera Rubin Telescope and CMB-S4 will discover many more outer Kuiper belt objects and settle the question of whether the observed alignment is due to Planet Nine, modified gravity or merely due to an observational bias of the existing surveys. MOND gravity deviates from Newtonian gravity when the field is weak. It was originally developed to account for galaxy rotation curves without invoking dark matter. Thus the Kuiper belt, which is a subject of great intrinsic interest, may also prove a laboratory for studying fundamental physics.
Reference - Kate Brown and Harsh Mathur, arXiv:2304.00576; to be published in the Astronomical Journal",https://events.umich.edu/event/111632,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111504-21827196,"2023-09-12 16:00:00","2023-09-12 17:00:00","CM-AMO Seminar | Extreme Light-Matter Interactions in Two-Dimensional Materials","Yuki Kobayashi (U-M Department of Chemistry)","Workshop / Seminar","When the field strength of the light approaches the internal Coulomb force of materials, it can be used to control their electronic properties by inducing nonequilibrium quantum states. In this talk, the potential of such intense light-matter interactions in novel two dimensional materials will be discussed, with special emphasis on energy state control and extreme nonlinear optics. These experiments are enabled by the development of powerful mid-infrared light sources that can efficiently access internal resonance of electron-hole states, known as excitons, while avoiding sample damage that may result from direct photoabsorption. First part of the talk presents energy state control of two-dimensional materials beyond the perturbative regime, wherein a light-dressed replica and giant blue shift of excitonic states are characterized. The second part of the talk shows the unique application of artificially stacked materials to realize nonlinear optical processes of high-harmonic generation with enhanced efficiency. These findings demonstrate the exciting opportunities of harnessing quantum dynamics beyond perturbation in two-dimensional materials.
Yuki Kobayashi is an Assistant Professor in the Department of Chemistry at the University of Michigan. His research group at the U-M Chemistry is committed to developing new tools in spectroscopy, such as attosecond x-ray light sources, and using them to solve complex chemical/materials problems. Yuki graduated from the University of Tokyo with a degree in chemistry and from the University of Califoria, Berkeley in 2020 with a PhD in Chemistry with Stephen Leone and Daniel Neumark. He was a postdoctoral fellow with Tony Heinz, David Reis, and Shambhu Ghimire at Stanford/SLAC from 2020-2023, and joined the U-M faculty in 2023. Yuki was selected for UC President’s Lindau Nobel Laureate Meetings Fellow at University of California, and also for Urbanek-Chorodow Postdoctoral Fellow at Stanford University.",https://events.umich.edu/event/111504,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
111679-21827409,"2023-09-13 15:00:00","2023-09-13 16:00:00","Department Colloquium | Studying Properties of the Higgs Boson with the High-Luminosity LHC","Tom Schwarz (U-M Physics)","Workshop / Seminar","The discovery of the Higgs Boson at the Large Hadron Collider (LHC) has necessitated the development of a large-scale physics program measuring the properties of the Higgs mechanism and searching for new physics associated with it. Within the next decade, the LHC will undergo multiple upgrades to dramatically increase the luminosity of the LHC. The resulting data will be almost a factor of ten larger than our current collected data, allowing for precision measurements of the properties of the Higgs. In this talk, I will discuss some of the more exciting properties of the Higgs currently being explored with the ATLAS experiment, as well as future physics that may be accessible with the larger dataset.",https://events.umich.edu/event/111679,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
110280-21824726,"2023-09-14 13:00:00","2023-09-14 16:00:00","Open House - CoE Naval Architecture & Marine Engineering","Aaron Friedman Marine Hydrodynamics Laboratory","Reception / Open House","Welcome to the University of Michigan's College of Engineering Open House event! Are you curious about the exciting field of Naval Architecture and Marine Engineering? Look no further! Our event is your chance to explore the cutting-edge research and state-of-the-art facilities of our department, and learn directly from our esteemed faculty and students.
At our event, you'll have the opportunity to:
1. Learn about the Naval Architecture and Marine Engineering program
2. Receive a tour of our laboratory specializing in hydrodynamics
3. Learn about advanced research at the lab and department level
4. Speak with current undergraduate and graduate students
5. Take a ride on the towing tank carriage
Join us at our Open House event to learn more about how our department can help you achieve your academic and professional goals",https://events.umich.edu/event/110280,"West Hall",,"West Hall",,"Engineering
Fluid Dynamics
Graduate Students
Hydrodynamic
Renewable Energy
Research
Student Org
Undergraduate Students","Naval Architecture & Marine Engineering"
112249-21828653,"2023-09-14 15:30:00","2023-09-14 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents","Dr. Jake Turner, Hubble Research Fellow, Cornell University","Lecture / Discussion","""The ongoing hunt to detect radio emission from the Tau Bootis exoplanetary system""
One of the most important properties of exoplanets has not yet been directly detected despite decades of searching: the presence of a magnetic field. Observations of an exoplanet’s magnetic field would yield constraints on its planetary properties that are difficult to study, such as its interior structure, atmospheric escape and dynamics, and any star-planet interactions. The presence of magnetic fields on gas giants also affects the understanding of their origins and evolution. Additionally, magnetic fields may contribute to the habitability of terrestrial exoplanets. Observing planetary auroral radio emission is the most promising method to detect exoplanetary magnetic fields.",https://events.umich.edu/event/112249,"West Hall",411,"West Hall",,astronomy,"Department of Astronomy
Michigan Institute for Research in Astrophysics"
110515-21825004,"2023-09-14 16:00:00","2023-09-14 17:00:00","Interdisciplinary QC-CM Seminar | Multi-Gap Topological Physics: Geometrical Notions, Physical Phases and Novel Responses","Robert-Jan Slager ( University of Cambridge)","Workshop / Seminar","I will review recent work on multi-gap topological states. These phases are characterized by topological structures that cannot be captured by advances in more conventional symmetry-based topological classifications schemes. Upon utilizing new insights into connections with general geometric identities I will elucidate the structure of these phases and highlight physical signatures in both equilibrium and out-of-equilibrium settings. These signatures are increasingly finding pathways to the laboratory in contexts that range from meta-materials and quantum simulators to electronic and phononic structures in real material candidates. As a highlight I will address how this understanding vice versa also relates to new takes on formulating novel quantum geometrical framework that can be probed by physical responses.",https://events.umich.edu/event/110515,"West Hall",335,"West Hall",,"Basic Science
Physics","Interdisciplinary QC/CM Seminars
Department of Physics"
112252-21828655,"2023-09-15 09:30:00","2023-09-15 10:20:00","Department of Astronomy 2023-2024 DEI Series Presents:","Dr. Jake Turner, Hubble Research Fellow, Cornell University","Lecture / Discussion","""My journey from rural Colorado to becoming an Astronomer""
In this talk, I will discuss my life journey to becoming an Astonomer. My childhood, career path, and current identities give me the empathy to understand the barriers that exist for underrepresented groups in academia. I grew up in a low socioeconomic environment in a small rural town in Colorado. We lived under the poverty line and I am a first-generation college student. My hometown had higher-than-average rates of poverty, teen pregnancy, and drug overdose deaths. During my childhood, my family dealt with alcoholic, mental health, and drug problems. I became interested in astronomy early in high school after attending a public star party. Subsequently, I received a scholarship to attend Astronomy Camp at the University of Arizona (UofA) and this camp influenced me greatly in choosing astronomy as a career. I also received a full-ride scholarship to attend UofA for my undergraduate degree and without this support I might have not been able to attend college. Today, I am disabled and identify as part of the LGBTQIA+ community. My lived experience helped me personally understand how public outreach and mentoring can have a profound impact on an individual’s life and help increase Diversity, Equity, and Inclusion (DEI) in Astronomy.",https://events.umich.edu/event/112252,"West Hall",411,"West Hall",,astronomy,"Department of Astronomy
Michigan Institute for Research in Astrophysics"
109423-21822011,"2023-09-15 10:00:00","2023-09-15 11:00:00","Statistics Department Seminar Series: Kean Ming Tan, Assistant Professor, Department of Statistics, University of Michigan","""Expected Shortfall Regression and Its Applications""","Workshop / Seminar","Abstract: The expected shortfall is defined as the average over the tail below (or above) a certain quantile of a probability distribution. The expected shortfall regression provides powerful tools for learning the relationship between a response variable and a set of covariates while exploring the heterogeneous effects of the covariates. In the health disparity research, for example, the lower/upper tail of the conditional distribution of a health-related outcome, given covariates, is often of importance. Motivated by the idea of using Neyman-orthogonal scores to reduce sensitivity to nuisance parameters, we consider a computationally efficient two-step procedure for estimating the expected shortfall regression coefficients. We establish explicit non-asymptotic bounds on the resulting estimator that lay down the foundation for performing statistical inference under different scenarios: (i) classical setting with $pn$; and (iii) under heavy-tailed random noise.
http://www.keanmingtan.com/",https://events.umich.edu/event/109423,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
111580-21827270,"2023-09-18 15:00:00","2023-09-18 16:00:00","HEP-Astro Seminar | nEXO: Probing New Physics With Ultra-Rare Decays","Ethan Brown (Rensselaer Polytechnic Institute)","Workshop / Seminar","The discovery of non-zero neutrino masses is the only measurement to date that violates standard model predictions, and opens exciting new possibilities for explanations of fundamental questions like the matter-antimatter asymmetry in the universe and the origin of neutrino masses. Neutrinoless double beta decay, an ultra-rare decay that will occur if and only if the neutrino and antineutrino are the same particle, may be one of the best probes for these questions. But since the half-life is greater than 10^26 years (compared to the age of the universe at 10^10 years), experiments must look for incredibly rare interactions in the most radio-pure environment ever constructed. One of the leaders for the next generation in the field is nEXO, a 5 ton experiment that will probe half-lives beyond 10^28 years. This talk will describe how nEXO will tackle this gargantuan task.",https://events.umich.edu/event/111580,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
112442-21828928,"2023-09-19 16:00:00","2023-09-19 17:00:00","CM-AMO Seminar | New molecules and field sensors with Rydberg atoms","Alisher Duspayev (U-M Physics)","Workshop / Seminar","This talk is focused on using neutral atoms in highly-excited (Rydberg) states for creating long-range molecular bonds and for sensing AC/DC electric fields. First, a new molecular ion formed through electric multipole interactions between a Rydberg atom and an ion is presented. Its vibrational spectra and stability against nonadiabatic effects will be discussed. In the second part, I will present our recent experimental investigations on whether Rydberg-atom-based sensing would be practical for electric microfields that occur in ion clouds and plasmas. The talk will be concluded with a discussion of the ongoing efforts to use high-angular-momentum Rydberg states for electric-field sensing in room-temperature vapor cells.",https://events.umich.edu/event/112442,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
111680-21827412,"2023-09-20 15:00:00","2023-09-20 16:00:00","Department Colloquium | Challenging the Standard Model with a new measurement of the muon magnetic moment anomaly g-2","Tim Chupp (U-M Physics)","Workshop / Seminar","The muon magnetic moment anomaly is a contribution to the magnetic moment that arises from interactions with the particles that briefly emerge from the quantum vacuum to affect the muon's interaction with a magnetic field. The muon g-2 experiment at Fermilab has collected six years of data, and on August 7, 2023, the collaboration announced the result from analyzing year two and three and the combined precision of 200 parts per-billion. In the Standard Model of particles and interactions, the muon g-2 is a radiative correction that can be calculated, in principle, with high precision. Our challenge to the Standard Model is the comparison of experiment and the theory. In this address, I will describe the experiment and the challenges overcome to achieve its precision with some emphasis on the University of Michigan contributions, and I will put the challenge to the Standard Model in context including the challenges of the Standard Model Calculation.",https://events.umich.edu/event/111680,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
112771-21829532,"2023-09-21 15:30:00","2023-09-21 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Yiting Li and Dr. Behzad Tahmasebzadeh Post Doc Colloquium","Lecture / Discussion","Yiting’s Title: Resolved Orbits around Accelerating Stars with RV, Direct Imaging and Astrometry
Astrometry, a time-honored planet detection technique, has thus far revealed only one gas giant planet while holding untapped potential for both ground- and space-based telescopes. This talk explores the use of Hipparcos and Gaia catalog data as an astrometry method to determine exoplanet masses. I discuss how integrating astrometry with direct imaging and radial velocity measurements can disentangle orbital curvatures, constrain precise dynamical masses, and improve target selection for direct imaging surveys focused on young, accelerating stars. Our ongoing direct imaging survey, conducted with the Keck/Subaru/SCAxAO and Keck/NIRC2 instruments, has unveiled a plethora of newly discovered substellar companions. These discoveries are contributing to the refinement of substellar evolutionary models and the rigorous testing of atmospheric models for giant planets and brown dwarfs. I will also briefly discuss future research interests, including TOLIMAN, a NASA-JPL astrometry mission to search for earth analog around the nearest binary stars, new ground-based observations and JWST initiatives, and exoplanet demographic studies.
Behzad’s Title: Do Massive Black Holes Come in Small Packages?
The mass function of black holes (BH) at lower masses remains poorly constrained in the local universe due to observational challenges. The occupation fraction of BHs within low-mass galaxy hosts, like compact stellar systems (CSSs), is essential for competing theories on supermassive BH (SMBH) formation. Stellar dynamical modeling has been successful in constraining the masses of central BHs in the cores of CSSs. I will discuss the power and limitations of our dynamical modeling approach to determine the black hole masses for CSSs in the Virgo cluster by JWST NIRSpec. We obtained JWST+NIRSpec/IFU data cubes to derive spatially resolved stellar kinematics of 18 selected CSSs in the Virgo Cluster. We will apply our method to determine the black hole masses in these CSSs, which is the first-ever census of CSS BHs in the Virgo galaxy cluster.",https://events.umich.edu/event/112771,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
111750-21827536,"2023-09-25 15:00:00","2023-09-25 16:00:00","HEP-Astro Seminar | Origins of Stars, Planets, and Life (?): Highlights from the First Year of Science from the NASA/ESA/CSA JWST","Michael R. Meyer (Department of Astronomy)","Workshop / Seminar","Over 20 years ago, the instrument teams for the NASA/ESA/CSA JWST outlined comprehensive science programs to answer to key questions concerning the origins of stars and planets, with implications as well for the origin of life. Deep observations of pre- and protostellar molecular cloud cores reveal the initial conditions of star formation, the composition of star- and planet-forming gas and dust, the first compact objects that form from collapse, and feedback from star formation which may contribute to self-regulation. Observations of brown dwarfs in young clusters and in the field, reveal multiplicity, atmospheric structure, and composition of these enigmatic objects that represent either the low mass end of the initial mass function or the high mass limit of planet formation. Imaging and spectroscopy of planet-forming circumstellar disks reveal how interstellar ingredients are transmuted into the building blocks of planets and the emergence of forming proto-planets in these disks. Observations of mature gas giants and brown dwarf companions as a function of host star mass, orbital separation, and mass ratio may reveal how the complex processes of planet formation determine their composition and help regulate the delivery of volatiles to potentially habitable planets. We will describe the power of JWST compared to complementary facilities, review relevant results from the first year of JWST science operations, and provide some hint of future exciting results to come.",https://events.umich.edu/event/111750,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111756-21827542,"2023-09-26 16:00:00","2023-09-26 17:00:00","CM-AMO Seminar | Combining Thermodynamic and Electronic Methods for Materials Design","Demet Usanmaz (Kettering University)","Workshop / Seminar","Exploiting advanced thermodynamic and electronic properties is an efficient way to design experimentally accessible novel materials. Consideration of formation enthalpy and thermodynamic phase diagrams, in which theoretical predictions rely on expensive computational methods, is crucial in predicting stability and synthesizability. In this talk, first, I will present an efficient method with low cost to predict thermodynamic phase diagrams based on formation enthalpy and Gibbs energy calculations. Next, I will share how this method can be employed to design experimentally accessible new topological phases and how different material engineering approaches—e.g., strain and thickness—can be used to investigate the controllability of these topological states.
Bio: Demet Usanmaz is an Assistant Professor of Physics in the Department of Natural Sciences at the Kettering University. She earned her Ph.D. in Physics at Gazi University in Turkey and moved to the University of Exeter, UK as a postdoctoral researcher. Before her current position, she was a postdoctoral associate at the Center for Autonomous Materials Design in the Department of Mechanical Engineering and Materials Science at Duke University. Dr. Usanmaz's current research focuses on designing new materials for clean energy and spintronics applications by investigating materials' thermodynamic and electronic properties using high-throughput ab initio methods. She received an NSF LEAPS-MPS award in 2023.",https://events.umich.edu/event/111756,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
111683-21827415,"2023-09-27 15:00:00","2023-09-27 16:00:00","Department Colloquium | The Black Hole Information Paradox: A Resolution on the Horizon?","Netta Engelhardt (MIT)","Workshop / Seminar","The black hole information paradox — whether information escapes an evaporating black hole or not— remains one of the most longstanding mysteries of theoretical physics. The apparent conflict between validity of semiclassical gravity at low energies and unitarity of quantum mechanics has long been expected to find its resolution in a complete quantum theory of gravity. Recent developments in the holographic dictionary, and in particular its application to entanglement and complexity, however, have shown that a semiclassical analysis of gravitational physics can reproduce a hallmark feature of unitary evolution. I will describe this recent progress and discuss some promising indications of a full resolution of the information paradox.",https://events.umich.edu/event/111683,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
113022-21829900,"2023-09-28 15:30:00","2023-09-28 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Vital Gutierrez Fernandez and Dr. Rachael Roettenbacher Post Doc Colloquium","Lecture / Discussion","Vital’s Title: Applying Machine Learning models in the analysis of large and complex spectroscopic data sets
Thanks to advancements in instrument design, upcoming sky surveys will generate as much data per day as the complete observations from completed surveys. Moreover, in the case of spectroscopy data sets, the increase in both wavelength range and instrument resolution will elevate the complexity of analyzing these observations to unprecedented levels. Consequently, existing algorithms must diversify their measurements while reducing the demands for both astronomer and computer time. In this presentation, I present my recent work on Green Peas galaxies. These are compact objects whose luminosity is dominated by a low metallicity star-forming burst. To improve the chemodynamic analysis of these objects, we have developed LiMe, a feature rich LIne MEasuring package (https://lime-stable.readthedocs.io/). Additionally, we demonstrate how this library can be employed to create your own online repository for sharing spectroscopic measurements, as we have done with the CEERs field JWST observations, spanning a 0 < z <10 range. Lastly, we discuss our future plans at University of Michigan, to leverage Machine Learning techniques to address the challenges posed by Astronomy Big Data.
Rachael’s Title: Starspots and the Search for Exoplanets
One way that the stellar magnetism of convective-envelope stars manifests is as starspots, which are localized regions of stifled convection. These cool surface features can affect the measurements of a star's fundamental stellar parameters, including radius and temperature, which ultimately lead to inaccurate estimates of mass and age. Starspots also can mimic or obscure the detections of exoplanets. As a result, an improved understanding of stellar surfaces is needed to be able to detect Earth-like planets around quiet Sun-like stars. My current work aims to use images of stellar surfaces to help disentangle the signatures of stars and their exoplanets. I will discuss the imaging techniques I use and my on-going project to image some of the closest Sun-like stars with sub-milliarcsecond resolution interferometric data. These surface images are used to model radial velocities for comparison with contemporaneous extreme precision radial velocity observations to improve our understanding of how stellar magnetism impacts the evidence and characterization of companions.",https://events.umich.edu/event/113022,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
107894-21818364,"2023-09-29 09:00:00","2023-09-29 17:00:00","Michael Woodroofe Memorial Conference","""Synergies between Nonparametrics, Sequential Analysis and Modern Data Science""","Conference / Symposium","In memorial to Professor Michael Woodroofe and his contributions to Statistics, the Department of Statistics at the University of Michigan, Ann Arbor, will be hosting a conference on September 29-30, 2023. The planned sessions for the conference include
*sequential analysis to reinforcement learning,
*shape constraints and beyond,
*limit theorems for dependent data,
*modern data science,
*nonparametrics and selection biases,
*astrostatistics in the 21st century.
The conference will feature around 20 talks mostly by Michael Woodroofe’s friends and co-authors, including also a few special talks by outstanding young researchers.
Confirmed Speakers
Persi Diaconis, Stanford University
Nancy Flournoy, University of Missouri
Dong-Yun Kim, National Institutes of Health
Tze Liang Lai, Stanford University
Mario Mateo, University of Michigan, Ann Arbor
Mary Meyer, Colorado State University
Magda Peligrad, University of Cincinnati
David Siegmund, Stanford University
Jiayang Sun, George Mason University
Dalibor Volný, Université de Rouen
Matthew Walker, Carnegie Mellon University
Jon Wellner, University of Washington
Xiao Wang, Purdue University
Wei Biao Wu, University of Chicago
Zhiliang Ying, Columbia University
Cui-Hui Zhang, Rutgers University
You can find the conference website here:https://sites.lsa.umich.edu/woodroofememorial/
Sponsors
The Caucus for Women in Statistics
Department of Statistics, Columbia University
Department of Statistics, University of Michigan, Ann Arbor
Wells Fargo
Welltower",https://events.umich.edu/event/107894,"West Hall",340,"West Hall",,conference,"Department of Statistics"
111193-21826195,"2023-09-29 15:00:00","2023-09-29 16:00:00","HET Seminar | Bootstrapping the CFT Landscape","David Poland (Yale)","Lecture / Discussion","From critical phenomena to quantum gravity, conformal field
theories (CFTs) describe the universal scale-invariant structures that lie at
the heart of theoretical physics. The conformal bootstrap is the
powerful idea, dating back to the 70’s, that one can use fundamental
consistency conditions to constrain, solve, and map out the space of
conformal field theories. In this talk I will describe recent progress in using
the conformal bootstrap to perform precise calculations and chart the
landscape of 3d CFTs involving interacting scalars, fermions, and gauge fields.",https://events.umich.edu/event/111193,"West Hall",335,"West Hall",,"High Energy Theory Seminar
physics","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
107894-21818365,"2023-09-30 09:00:00","2023-09-30 17:00:00","Michael Woodroofe Memorial Conference","""Synergies between Nonparametrics, Sequential Analysis and Modern Data Science""","Conference / Symposium","In memorial to Professor Michael Woodroofe and his contributions to Statistics, the Department of Statistics at the University of Michigan, Ann Arbor, will be hosting a conference on September 29-30, 2023. The planned sessions for the conference include
*sequential analysis to reinforcement learning,
*shape constraints and beyond,
*limit theorems for dependent data,
*modern data science,
*nonparametrics and selection biases,
*astrostatistics in the 21st century.
The conference will feature around 20 talks mostly by Michael Woodroofe’s friends and co-authors, including also a few special talks by outstanding young researchers.
Confirmed Speakers
Persi Diaconis, Stanford University
Nancy Flournoy, University of Missouri
Dong-Yun Kim, National Institutes of Health
Tze Liang Lai, Stanford University
Mario Mateo, University of Michigan, Ann Arbor
Mary Meyer, Colorado State University
Magda Peligrad, University of Cincinnati
David Siegmund, Stanford University
Jiayang Sun, George Mason University
Dalibor Volný, Université de Rouen
Matthew Walker, Carnegie Mellon University
Jon Wellner, University of Washington
Xiao Wang, Purdue University
Wei Biao Wu, University of Chicago
Zhiliang Ying, Columbia University
Cui-Hui Zhang, Rutgers University
You can find the conference website here:https://sites.lsa.umich.edu/woodroofememorial/
Sponsors
The Caucus for Women in Statistics
Department of Statistics, Columbia University
Department of Statistics, University of Michigan, Ann Arbor
Wells Fargo
Welltower",https://events.umich.edu/event/107894,"West Hall",340,"West Hall",,conference,"Department of Statistics"
113158-21830158,"2023-10-02 15:00:00","2023-10-02 16:00:00","HEP-Astro Seminar | The SPICE and HeRALD Experiments for Sub-GeV Dark Matter Direct Detection","Scott Hertel (University of Massachusetts)","Workshop / Seminar","The SPICE and HeRALD experiments aim to probe dark matter (DM) masses at the MeV masses via nuclear recoils. This sensitivity motivates R&D which is now pushing the recoil energy threshold of Transition Edge Sensors (TESs) into the meV regime before then applying these next-generation phonon sensors to a set of well-motivated target materials. The superfluid 4He target (HeRALD) will benefit from both a low-mass target nucleus and a unique quantum evaporation phonon readout method. The complementary SPICE effort employs polar crystal target materials, motivated by their low-momentum phonon states and strong coupling to dark photon couplings.",https://events.umich.edu/event/113158,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111757-21827543,"2023-10-03 16:00:00","2023-10-03 17:00:00","CM-AMO Seminar | Many-Body Dynamics in Atomic Arrays (Without Solving Equations)","Ana Asenjo Garcia (Columbia University)","Workshop / Seminar","Solving for the dynamics of many-body quantum systems is typically hard, unless there is a high degree of symmetry present. An example of the latter in the context of quantum optics is Dicke superradiance, where excited atoms self-organize as they decay, emitting a short and intense pulse of light. While well understood in a cavity, the problem of many-body decay in extended systems remains open, due to the exponential growth of complexity with atom number. In this talk, I will discuss how coherent behavior emerges in extended quantum systems, and how to understand the dynamics in atomic arrays without the need of heavy computation. Our analytical results provide insights on the critical role of dimensionality on the many-body dynamics, as well as point to universal behavior that is lattice-geometry independent. Our predictions can be tested in state of the art experiments with arrays of neutral atoms, and pave the way towards understanding the role of many-body decay in extended systems for metrology and lasing.",https://events.umich.edu/event/111757,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
111685-21827416,"2023-10-04 15:00:00","2023-10-04 16:00:00","Department Colloquium | The science of FRIB: From the nuclear many-body challenge to the origin of the elements in the Universe","Alexandra Gade (MSU)","Workshop / Seminar","There are approximately 300 stable and 3,000 known unstable (rare) isotopes. Estimates are that over 7,000 different isotopes are bound by the nuclear force. It is now recognized that the properties of many yet undiscovered rare isotopes hold the key to understanding how to develop a comprehensive and predictive model of atomic nuclei, to accurately model a variety of astrophysical environments, and to understand the origin and history of elements in the Universe. Some of these isotopes also offer the possibility to study nature's underlying fundamental symmetries and to explore new societal applications of rare isotopes. This presentation will give a glimpse of the opportunities that arise at the Facility for Rare Isotope Beams (FRIB) that started operations at Michigan State University in 2022.",https://events.umich.edu/event/111685,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
109424-21822012,"2023-10-06 10:00:00","2023-10-06 11:00:00","Statistics Department Seminar Series: Anne van Delft, Assistant Professor, Department of Statistics, Columbia University","""A statistical framework for analyzing shape in a time series of random geometric objects"" (joint work with Andrew J. Blumberg)","Workshop / Seminar","Abstract: We introduce a new framework to analyze shape descriptors that capture the geometric features of an ensemble of point clouds. At the core of our approach is the point of view that the data arises as sampled recordings from a metric
space-valued stochastic process, possibly of nonstationary nature, thereby integrating geometric data analysis into the realm of functional time series analysis. We focus on the descriptors coming from topological data analysis. Our framework allows for natural incorporation of spatial-temporal dynamics, heterogeneous sampling, and the study of convergence rates. Further, we derive complete invariants for classes of metric space-valued stochastic processes in the spirit of Gromov, and relate these invariants to so-called ball volume processes. Under mild dependence conditions, a weak invariance principle in $D([0,1]\times [0,\mathscr{R}])$ is established for sequential empirical versions of the latter, assuming the probabilistic structure possibly changes over time. Finally, we use this result to introduce novel test statistics for
topological change, which are distribution free in the limit under the hypothesis of stationarity. https://arxiv.org/pdf/2304.01984.pdf
https://sites.google.com/view/anne-van-delft/home",https://events.umich.edu/event/109424,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
111196-21826212,"2023-10-06 15:00:00","2023-10-06 16:00:00","HET Seminar | Progress & Challenges for Direct-Detection of Sub-GeV Dark Matter","Rouven Essig (Stony Brook)","Lecture / Discussion","The search for dark matter with masses between meV-to-GeV has seen tremendous theoretical and experimental progress in the past few years. I will provide an overview of some of this progress. I will mention recent results from SENSEI, a Skipper-CCD-based experiment that is sensitive to (halo) dark matter scattering off electrons for masses larger than ~1 MeV. I will highlight how such detectors can, however, also probe sub-MeV dark matter masses by searching for the component of dark matter that is boosted to higher energies from scattering in the Sun. In particular, future detectors with larger exposures could probe the entire “freeze-in” benchmark model down to keV masses. I will also discuss some challenges for direct detection, in particular, novel low-energy backgrounds. I will introduce a new detector concept, the “dual-sided CCD”, which could help with distinguishing some of these backgrounds.",https://events.umich.edu/event/111196,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
112203-21828589,"2023-10-06 16:00:00","2023-10-06 17:30:00","CSAS Kavita Datla Memorial Lecture | Urdu's Intoxicated Mirror: Maharaja Kishan Parshad and Indian History","Syed Akbar Hyder, Associate Professor, Department of Asian Studies, University of Texas at Austin","Lecture / Discussion","Inspired by Kavita Datla’s pioneering work on Osmania University, Hyder explores the legacy of Maharaja Kishan Parshad “Shād” (1864-1940), the illustrious prime minister of the princely state of Hyderabad.
Attend in person or via Zoom at: https://umich.zoom.us/j/91065678467
Apart from being a committed educator and a visionary behind the university, “Shād” also cultivated a style of history writing informed by Perso-Urdu poetic sensibilities that challenged parochial readings of religion, region, gender, and beauty. Through his intervention in the development of several literary genres, he navigated challenging issues of nationalism and colonialism, bringing Hyderabad into a conversation with the larger world of letters, a world that featured Delhi's Khwaja Hasan Nizami and Lahore's Muhammad Iqbal.
Syed Akbar Hyder is an associate professor of Asian Studies and Islamic Studies at the University of Texas at Austin. He is also affiliated with the university's program in comparative literature. His research interests are anchored in comparative aesthetics, devotional literature, and the politics of canon formation in Urdu, Hindi, and Persian. His forthcoming publication is *A City, an Island, and a Jail: Qurratulain Hyder on the Move.*
The lecture is made possible through the generosity of Dr. Kavita Datla's family and friends.
If there is anything we can do to make this event accessible to you, please contact us. Please be aware that advance notice is necessary as some accommodations may require more time for the university to arrange.",https://events.umich.edu/event/112203,"West Hall","Room 411","West Hall",,"Asia
Pakistan","Center for South Asian Studies
International Institute
Asian Languages and Cultures"
111910-21827882,"2023-10-09 15:00:00","2023-10-09 16:00:00","HEP-Astro Seminar | Eyes on the Sky: How 5,000 Robots are Unraveling the Mystery of Dark Energy","Abby Bault (University of California, Irvine)","Workshop / Seminar","The Dark Energy Spectroscopic Instrument (DESI) is currently constructing the largest 3D map of the universe to date. By the end of its 5 year survey, DESI will have collected spectra of 40 million extra-galactic objects which will be used to measure the effect of dark energy on the expansion of the universe. To do this DESI is utilizing 5,000 robots to precisely align fibers about as thick as a human hair to collect the light that has travelled billions of years from distant galaxies. In this talk I will discuss how some of these robots seem to have a mind of their own, and also show some preliminary results using data from DESI’s 5,000 eyes.",https://events.umich.edu/event/111910,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111758-21827544,"2023-10-10 16:00:00","2023-10-10 17:00:00","CM-AMO Seminar | Electronic Phase Diagram of Cuprate Superconductors","Makoto Hashimoto (SLAC)","Workshop / Seminar","High-temperature superconductivity in copper-based materials, with critical temperature well above what was anticipated by the BCS theory, remains a major unsolved physics problem more than 30 years after its discovery. The problem is fascinating because it is simultaneously simple - being a single band and ½ spin system, yet extremely rich - d-wave superconductivity, pseudogap, spin and charge orders, and strange metal. The resulting electronic phase diagram consists of intertwined states with unusual properties. As such, the cuprates remain as the most important model system for correlated electrons.
Angle-resolved photoemission spectroscopy (ARPES) has emerged as the leading experimental tool to understand the electronic structure of these states and their relationships [1]. In this talk, I will describe our recent progress on the subjects. With the instrumentation improvements, ARPES measurements in the normal state with unprecedented precision became possible in hole-doped cuprates Bi_2 Sr_2 Ca Cu_2 O_{8+δ}. Our study revealed that the incoherent strange metal abruptly reconstructs into a more conventional metal with quasiparticles across the putative critical doping around 19%, defining a temperature-independent vertical phase boundary [2], providing insights into the nature of the pseudogap, strange metal, and putative quantum critical point. In the overdoped regime above such critical doping, an unconventional signature of Tc in the spectral weight was revealed, making direct semi quantitative connection between ARPES spectra and thermodynamic property [3]. More recently, our ARPES studies were expanded to the electron-doped cuprates Nd_{2–x} Ce_x Cu O_4, leading to the observation of Bogoliubov quasiparticle peaks in this system, revealing how the superconductivity emerges under the influence of antiferromagnetic correlations [4]. Time permits, I will also show our results from oxide MBE grown thin films. I will discuss the benchmarking of 1D Hubbard model and the necessity of an additional attractive term to describe the doped 1D cuprate chains Ba_{2-x} Sr_x Cu O_{3+δ [5]. In thin-film La_{2-x} Sr_x Cu O_4, the Lifshitz transition around 19% doping was revealed, and its impact on specific heat and the phase diagram will be discussed [6].
[1] M. Hashimoto, I. M. Vishik, R.-H. He, T. P. Devereaux, Z.-X. Shen, Nat Phys 10, 483 (2014)
[2] S. Chen et al. Science 366, 6469 (2019)
[3] S. Chen et al., Nature 601, 562 (2022)
[4] K. Xu et al., Nature Phys, in press
[5] Z. Chen et al., Science 373, 6560 (2021)
[6] Y. Zhong et al., PNAS 119, e2204630119 (2022)",https://events.umich.edu/event/111758,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
113556-21831152,"2023-10-12 15:30:00","2023-10-12 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Stefano Facchini, Associate Professor, University of Milan","Lecture / Discussion","""Unveiling the infancy of planetary systems""
The large variety of observed planetary systems is rooted in the complex physical and chemical processes that lead to their formation. In the last few years, great observational and theoretical developments have dramatically improved our understanding of how forming planets are affected by and interact with their birth environments, the protoplanetary disks. In this talk, I will show how physical and chemical processes in disks concur in promoting conditions amenable for planet formation. I will focus on novel methodologies to detect forming planets and circumplanetary disks from ALMA data, in particular in the kinematical structure of protoplanetary disks. I will finally discuss present challenges and upcoming developments in this exciting field, focusing on new and upcoming data from ALMA, JWST and 30m class telescopes.",https://events.umich.edu/event/113556,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
113596-21831200,"2023-10-13 10:00:00","2023-10-13 11:00:00","Statistics Department Seminar Series: Ben Hansen, Associate Professor, Department of Statistics, University of Michigan.","""Objects in propensity-matched pairs are farther than they appear""","Workshop / Seminar","Abstract: To match closely on a propensity, prognostic or other index score is harder than it would appear. Nearest-neighbor matching may closely align subjects on an estimate of the score, particularly when permitted to exclude subjects without nearby counterparts. Yet even after matching within strict tolerances, on a well-specified and efficiently estimated index, paired differences on actual scores can be surprisingly large. A first contribution of this research is to marshall evidence that univariate propensity score matching typically does leave large discrepancies on an underlying true score, regardless of how closely one matches on estimated scores. Even the luxury (a) of well-behaved (sub-gaussian) covariates that are (b) of moderate dimension (d=o(√n)) does not in itself address the problem. Nor does (c) strict overlap between intervention and control groups (all propensities within [a,b] ⊆ (0,1)), or matching in observance of caliper restrictions as suggested in extant literature. These conclusions are supported by insights from high-dimensional probability, and illustrated with health policy examples.
There's good news as well. When (a) and (b) are satisfied, estimation errors of the scores tend uniformly to zero, having sizes that are themselves estimable and can be summarized with a single number. That number in turn suggests a new caliper criterion that rejects few or no pairings that are close on the underlying score, yet is restrictive enough to cause index differences within the *matched* sample to tend uniformly to 0. None of (a)-(c) is required for this, although all will be true of the matched sample if the matching procedure has been governed by a caliper of the proposed type. The presentation will focus on propensity scores, but similar considerations apply to prognostic scores, principal scores and predictive mean matching.",https://events.umich.edu/event/113596,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
111686-21827418,"2023-10-18 15:00:00","2023-10-18 16:00:00","Department Colloquium | How a Pendulum Clock Knows the Difference Between the Past and the Future","David Albert (Columbia University)","Workshop / Seminar","There is a long-cherished hope, which has its origins in the work of Boltzmann, that all that we are going to need to do, in order to account for all the differences there are between the past and the future, is to add to the fundamental time-reversal-symmetric dynamical laws, and to the standard statistical-mechanical probability-measure over the space of possible fundamental physical states, a simple postulate – a so-called “past hypothesis” – about the initial microstate of the universe as a whole. And there are various widespread and and perennial sorts of puzzlement about how a hope like that can even seriously be entertained – puzzlements (that is) about how it is that the macrocondition of the universe 15 billion years ago, all by itself, can even imaginably be up to the job of explaining so much about the feel, today and on earth, of the passing of time. I want to try to alleviate those puzzlements here. I will begin with a number of very general observations – and then, by way of illustration, I will present a new and detailed analysis of how it is that a simple pendulum clock invariably arranges to turn its hands clockwise in the temporal direction that points away from the Big Bang.",https://events.umich.edu/event/111686,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
114097-21832339,"2023-10-19 15:30:00","2023-10-19 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Floor Broekgaarden, Junior Fellow, Simons Society of Fellows at CCA/Columbia U./Flatiron Institute","Lecture / Discussion","""Gravitational Wave Paleontology: a New Frontier to Probe the Lives of Massive Binary Stars across Cosmic History""
The rapidly increasing population of double compact object mergers detected with gravitational waves provides an unprecedented probe of the physics of black holes and neutron stars, and of the evolution of the binary massive stars that formed them. This will open the new frontier of `gravitational-wave paleontology’: studying massive stars and binary evolution from their ‘remnant’ compact object mergers, with the goal of answering some of the biggest open questions in astrophysics today: How do these gravitational-wave sources form? What can we learn from them about the formation, lives, and explosive deaths of massive stars across cosmic time? How do these sources help to enrich the universe with heavy metals? In this talk, I will outline the key bottleneck in gravitational-wave paleontology: the gravitational-wave progenitor Uncertainty Challenge. I will present how we aim to quantify and understand the key uncertainties in theoretical models of the formation of gravitational-wave sources focusing on the formation from isolated massive binary stars, with the key goal to use the rapidly growing population of gravitational-wave observations as a new probe of the formation, lives, and deaths of massive binary stars through cosmic history.",https://events.umich.edu/event/114097,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
114100-21832340,"2023-10-20 09:30:00","2023-10-20 10:20:00","Department of Astronomy 2023-2024 DEI Series Presents:","Dr. Floor Broekgaarden, Junior Fellow, Simons Society of Fellows at CCA/Columbia U./Flatiron Institute","Lecture / Discussion","""Ten Ways to Improve Resources to avoid and mitigate Harassment in Astronomy/Physics:""
Many scientists experience workplace incivility including bullying, (sexual) harassment, or racism in their career (either as target or witness). Finding support to navigate such situations is important, yet challenging, especially for early-career astronomers and underrepresented minorities. This contributes to the structural exclusion of those that experience or witness workplace incivility from our astronomy community. Here I suggest ten ways that departments, institutes, collaborations, and conference organizers can improve support for astronomers that experience or witness workplace incivility. Session will be discussion based.",https://events.umich.edu/event/114100,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
113640-21831298,"2023-10-20 10:00:00","2023-10-20 11:00:00","Statistics Department Seminar Series: Zhenke Wu, Associate Professor, Department of Biostatistics, University of Michigan","""Tree-Regularized Bayesian Latent Class Analysis: Improving Weakly Separated Dietary Pattern Subtyping in Small-Sized Subpopulation""","Workshop / Seminar","Dietary patterns synthesize multiple related diet components, which can be used by nutrition researchers to examine diet-disease relationships. Latent class models (LCMs) have been used to derive dietary patterns from dietary intake assessment, where each class profile represents the probabilities of exposure to a set of diet components. However, LCM-derived dietary patterns can exhibit strong similarities, or weak separation, resulting in numerical and inferential instabilities that challenge scientific interpretation. This issue is exacerbated in small-sized subpopulations. To address these issues, we provide a simple solution that empowers LCMs to improve dietary pattern estimation. We develop a tree-regularized Bayesian LCM that shares statistical strength between dietary patterns to make better estimates using limited data. This is achieved via a Dirichlet diffusion tree process that specifies a prior distribution for the unknown tree over classes. Dietary patterns that share proximity to one another in the tree are shrunk towards ancestral dietary patterns a priori, with the degree of shrinkage varying across pre-specified food groups. Using dietary intake data from the Hispanic Community Health Study/Study of Latinos, we apply the proposed approach to a sample of 496 US adults of South American ethnic background to identify and compare dietary patterns.
https://zhenkewu.com/",https://events.umich.edu/event/113640,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
113972-21831977,"2023-10-20 12:00:00","2023-10-20 13:00:00","LAGS Seminar | Why Your Physics PhD Matters (And Why I Value Mine)","Steven Wolgast (Team Lead for Advanced Product Development at NanoFlex Power Corporation)","Workshop / Seminar","By the time I started college, I expected to end up as an academic professor, but plans changed a year after finishing grad school. In the few years since then, I've been working on solar cell commercialization at NanoFlex Power Corporation. In this talk, I will share my motivations for and experience with this change of course, highlighting how my very narrowly focused PhD research experience still does the heavy lifting for me in a mostly unrelated technical field outside academia.",https://events.umich.edu/event/113972,"West Hall",335,"West Hall",,"Physics
Science","Life After Grad School Seminars
Department of Physics"
111913-21827884,"2023-10-23 15:00:00","2023-10-23 16:00:00","HEP-Astro Seminar | X-Ray -- Cosmic Shear Cross-Correlations: First Detection and Constraints on Baryonic Effects","Tássia Ferreira (University of Oxford)","Workshop / Seminar","In this presentation, I will discuss the recent discovery of the cross-correlation between cosmic shear and the diffuse X-ray background. This correlation is extremely important for cosmological and astrophysical analyses, as it enables us to impose precise constraints on critical physical parameters governing the impact of baryonic effects on the matter power spectrum. Specifically, we obtain strong bounds for the parameter describing the average mass of haloes at which feedback mechanisms have expelled half of their gas content, \log_{10}(M_c/M_\odot). I will explain the data sets used, the theoretical models considered and conclude with our results and steps for future analyses.",https://events.umich.edu/event/111913,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111760-21827546,"2023-10-24 16:00:00","2023-10-24 17:00:00","CM-AMO Seminar | Two-Dimensional Trapped Ion Crystals, Micromotion and Qubit State Detection","Boris Blinov (University of Washington)","Workshop / Seminar","To study potential avenues for scaling up trapped ion crystal size, we built a modified Paul trap with an oblate aspect ratio designed for trapping radial 2-d ion crystals. In this geometry, the micromotion can only be minimized in the axial direction, transverse to the crystal plane. The in-plane micromotion is unavoidable, its amplitude increasing linearly with distance from the trap center. Thus, different ions in a large crystal experience different micromotion amplitudes, and different Doppler shifts, making traditional laser cooling techniques inefficient. We explored two avenues towards improving the laser cooling efficiency: the two-tone laser cooling and the micromotion-synchronized pulsed Doppler cooling, allowing us to stabilize larger 2-d crystals than with the traditional Doppler cooling.
These experiments were enabled in part by the novel imaging system based on a CMOS camera that allows 1.5 ns temporal resolution of single photon detection. Direct observation of the trapped ion micromotion is attainable with this camera, leading to a simplified way of micromotion detection and compensation. We also demonstrated how this camera can be used for robust, low crosstalk detection of a trapped Ba+ ion qubit register, with average single-qubit detection error of 4.2(1.5) ppm and a four-qubit state detection error of 17(2) ppm, limited by the decay lifetime of the qubit.",https://events.umich.edu/event/111760,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
111611-21827321,"2023-10-25 16:15:00","2023-10-25 17:15:00","AIM Seminar/MCAIM Colloquium: Edge effects at insulator interfaces, acoustic simulations, and modeling optics in the miniwasp eye","Manas Rachh, Flatiron Institute","Lecture / Discussion","The numerical simulation of wave scattering processes plays a critical role in chip and antenna design, radar cross section determination, biomedical imaging, wireless communications, and the development of new meta-materials and better waveguides to name a few. In order to enable design by simulation for problems arising in these applications, automatically adaptive solvers which resolve the complexity of the geometry and the input data, and combining these tools with neural networks to navigate the complicated design-optimization landscape play a critical role. On the adaptive solvers side, this has been made possible through the development of high-order integral equation methods which rely on well-conditioned integral representations, efficient quadrature formulas, and coupling to fast algorithms. In this talk, I will discuss the development and application of these tools for a) studying edge effects at insulator interfaces where waves tend to propagate at the interface of two insulating media (and are evanescent in the bulk); b) an industry collaboration with Meyer Sound for optimizing the design of horn-loaded speakers; and c) studying light propagation in an insect eye.
Talk will be in-person and on Zoom:
https://umich.zoom.us/j/98734707290
Contact: Shravan Veerapaneni",https://events.umich.edu/event/111611,"West Hall",120,"West Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics
MCAIM Colloquium - Department of Mathematics"
114228-21832523,"2023-10-26 15:30:00","2023-10-26 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Misty C. Bentz, Professor, Georgia State University","Lecture / Discussion","""Comparing Direct Black Hole Mass Measurements in AGNs""
Supermassive black holes appear to be ubiquitous in the nuclei of massive galaxies, and several large-scale galaxy properties have been to found to scale with black hole mass, giving rise to the idea that galaxies and their black holes likely co-evolve. There are only a few techniques that can directly constrain the mass of a black hole through its gravitational influence on luminous matter, of which the most commonly applied are reverberation mapping and stellar or gas dynamical modeling. These techniques have been applied to a modest number of black holes, with the vast majority of black hole masses in the literature instead being estimates derived from scaling relationships that are based on direct measurements. Dynamical modeling results provide most commonly used scaling relationships for galaxies in the local universe, while outside the local universe, reverberation mapping results provide the foundation for AGN scaling relationships. Thus there are two different mass scales currently in use. Only a handful of black holes have masses that have been constrained through multiple techniques because of their disparate technical requirements. In AGNs, the situation is even worse because active galaxies are rare and most are too far away to allow the spatial resolution needed for dynamical modeling. I will describe our ongoing project to directly compare black hole masses from reverberation mapping and stellar dynamical modeling in the nearest Type 1 Seyferts. Both reverberation mapping and stellar dynamical modeling are time- and resource-intensive techniques and the number of galaxies we can study is small, but the results will help uncover potential biases in these direct mass techniques and illuminate any differences in the black hole mass scales that are applied locally versus at cosmological distances.",https://events.umich.edu/event/114228,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
114229-21832524,"2023-10-27 09:30:00","2023-10-27 10:20:00","Department of Astronomy 2023-2024 DEI Series Presents:","Dr. Misty C. Bentz, Professor, Georgia State University","Lecture / Discussion","""Equity issues in scientific publishing""
In June 2023, I began a term as Chair of the AAS Publications Committee. The PC provides independent oversight of AAS Journals (AJ, ApJ, ApJS, ApJL, PSJ, RNAAS) and acts as a direct conduit between the community and the Journals staff. Much of our current and ongoing work on the PC involves advancing equity in scientific publishing. I will briefly highlight some recent efforts, including the AAS Publication Support Fund and the AAS Journals referee training program, and a portion of the time will be reserved for discussion and dialogue.",https://events.umich.edu/event/114229,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
109433-21822022,"2023-10-27 10:00:00","2023-10-27 11:00:00","Statistics Department Seminar Series: Claire Bowen, Principal Research Associate and Statistical Methods Group Lead for Data Privacy and Confidentiality, Urban Institute","""Safe Data Technologies Project: Safely Expanding Access to Administrative Tax Data""","Workshop / Seminar","Abstract: The Statistics of Income (SOI) Division within the Internal Revenue Service curates and maintains an extensive repository of tax data, offering researchers a valuable resource for evaluating the impacts of tax policies and exploring diverse research inquiries, including the analysis of income inequality. While the confidential data remains accessible only to a limited number of government analysts and researchers, SOI provides an accessible public use file for external researchers and data practitioners. However, safeguarding this public use file has grown increasingly difficult to protect through traditional statistical data privacy methods, as the vast amount of personal information available in public and private databases combined with enormous computational power create unprecedented privacy risks.
This presentation will cover the collaborative efforts of SOI and researchers at the Urban Institute, who are actively developing a solution: the creation of synthetic data that represent the statistical properties of the administrative data without revealing any individual taxpayer information. Additionally, Urban is building a prototype validation server that empowers researchers to indirectly conduct statistical analyses on administrative tax data. Researchers can accomplish this by evaluating their analyses using synthetic data and subsequently submitting them to the validation server. The server then produces a modified output with added noise, all the while maintaining the confidentiality of taxpayer information. In essence, this talk will address the lessons learned, best practices, and challenges encountered in the process of safely expanding access to administrative tax data.
https://clairemckaybowen.com/",https://events.umich.edu/event/109433,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
111199-21826215,"2023-10-27 15:00:00","2023-10-27 16:00:00","HET Seminar | New attractors for the black hole index","Sameer Murthy (King's College London/IAS)","Lecture / Discussion","The count of black hole microstates is typically obtained from a supersymmetric index in weakly coupled string theory. I will discuss the index in the strongly coupled theory, as a functional integral in N=2 supergravity in asymptotically flat space. The saddle-points of this index are given by supersymmetric ""finite-temperature"" rotating geometries. I will discuss a new version of the attractor mechanism obeyed by these geometries: the scalar fields at the poles of the Euclidean horizon as well as the free energy of the black hole get attracted to values that depend only on the charges and are independent of the asymptotic moduli and temperature.",https://events.umich.edu/event/111199,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
111914-21827886,"2023-10-30 15:00:00","2023-10-30 16:00:00","HEP-Astro Seminar | A “Cool” Route to Unveil the Higgs Boson’s Secrets","Caterina Vernieri (SLAC)","Workshop / Seminar","The Higgs boson was discovered in 2012 by the ATLAS and CMS experiments at the world’s most powerful particle collider, the Large Hadron Collider (LHC) in Geneva, Switzerland. This particle plays a unique role in fundamental physics. It gives all of the known elementary particles, including itself, their masses. While we now have a strong evidence that the Higgs field is indeed the unique source of mass for the known elementary particles, the next step is to search for new interactions that could also explain why the Higgs field has the properties required by the Standard Model of particle physics. We have no clear roadmap to this new theory but the Higgs boson plays a crucial role in this quest. The goal of a next-generation e+e- collider is to carry out precision measurements to per-cent level of the Higgs boson properties that are not accessible at the LHC and HL-LHC. In this talk we present the study of a new concept for a high gradient, high power accelerator, the Cool Copper Collider (C^3), that could provide a route to precision Higgs physics with a compact footprint. The exploitation of the complementarity between LHC and future colliders will be the key to understanding fundamentally the Higgs boson.",https://events.umich.edu/event/111914,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111761-21827547,"2023-10-31 16:00:00","2023-10-31 17:00:00","CM-AMO Seminar | Optical Control of Antiferromagnetic Order","Suyang Xu (Harvard University, Department of Chemistry and Chemical Biology)","Workshop / Seminar","Using circularly-polarized light to control quantum matter is a highly intriguing topic in physics, chemistry and biology. Antiferromagnets (AFMs) have zero net magnetization, so AFM domains are immune to perturbing magnetic field. This leads to the prospect of robust magnetic storage. However, this robustness also means that manipulating fully-compensated AFM order is extremely difficult. We report the surprising observation of helicity-dependent optical control of fully compensated antiferromagnetic (AFM) order in 2D even-layered MnBi2Te4, a topological Axion insulator no magnetization. We demonstrated helicity-dependent optical creation of AFM domain walls by double induction beams and the direct reversal of AFM domains by ultrafast pulses. The control and reversal of AFM domains and domain walls by light helicity have never been achieved in any fully-compensated AFM. To understand this optical control, we studied an AFM circular dichroism (CD) proportional to the AFM order, which only appears in reflection but is absent in transmission. We showed that the optical control and CD both arise from the optical Axion electrodynamics. The Axion induction provides the possibility to optically control a family of PT-symmetric AFMs such as Cr2O3, even-layered CrI3, and possibly pseudo-gap state in cuprates.
Reference:
J. Qiu, et al. “Axion optical induction of antiferromagnetic order” Nature Materials s41563-023-01493-5 (2023).
Bio: Suyang Xu received PhD in the Physics Department of Princeton University under the supervision of Prof. M. Zahid Hasan. During his phd, Xu experimentally realized a wide range of new topological phases of matter, including the discovery of the Weyl semimetal in the TaAs class of material, which was selected as a top10 breakthrough in physics in 2015. In 2016, Xu moved to MIT Physics for postdoc under the supervision of Prof. Nuh Gedik. There, Xu pioneered in nonlinear optical studies of topological materials including photocurrents, nonlinear Hall and second-harmonic generation. In 2020, Xu started his independent career in the department of Chemistry and Chemical Biology at Harvard as an assistant professor.",https://events.umich.edu/event/111761,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
114599-21833093,"2023-11-01 15:00:00","2023-11-01 16:00:00","Department Colloquium | Avoiding the Coming Climate Catastrophe","Stephen Forrest (U-M Departments of Physics, EECS and Materials Science and Engineering)","Workshop / Seminar","It is becoming increasingly apparent that climate change due to green house gas (GHG) emissions is accelerating, giving humanity less and less time to mitigate its ultimate effects on our global ecosystem. Interestingly, climate change was predicted (reasonably accurately) more than a century ago by Arrhenius, and then improved by Callendar in 1938 using better data, so you can’t say we weren’t warned. In this talk, I will discuss the history, the current state and future implications of anthropogenic climate change. In 2020, President Schlissel established the President’s Commission on Carbon Neutrality to develop a plan for U-M to do its part in meeting its own emission reduction strategy. I will discuss some of the important conclusions of that plan and the progress made thus far in achieving its goals. Finally, if there is time I will discuss solar technologies that can cost effectively have an enormous impact in reducing global use of fossil fuels in the near term.",https://events.umich.edu/event/114599,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
114453-21832895,"2023-11-02 15:30:00","2023-11-02 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Kristen Dage, NASA Einstein Fellow, Wayne State University","Lecture / Discussion","""Ultraluminous X-ray Sources in Extragalactic Globular Clusters""
Currently, ultraluminous X-ray sources (ULXs) with globular cluster (GC) counterparts have been identified. This is exciting, as ULXs have been theorized as potential intermediate mass black holes. New black hole mergers detected by LIGO-Virgo may also be associated with GC’s, underscoring the importance of ULXs as a potential linkage between GC electromagnetic and gravitational wave source populations. GC ULXs show a diverse behaviour with regards to temporal variability, both on long (16 years) and short (~hours) timescales, in both the X-ray and optical wavelengths. They can switch on or off over the course of many years or remain at a constant luminosity. Some sources exhibit a long-term change in their luminosity with no discernible variability within the other observations, other sources show a stunning long-term variability while also demonstrating variability on the timescale of around four hours. I will undertake a comprehensive comparison of the temporal variability of the zoo of currently known GC ULXs, discuss the possible origins of some of the extreme variability observed, and how this informs on our knowledge of black hole populations in extragalactic globular clusters.",https://events.umich.edu/event/114453,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
114454-21832896,"2023-11-03 09:30:00","2023-11-03 10:20:00","Department of Astronomy 2023-2024 DEI Series Presents:","Dr. Kristen Dage, NASA Einstein Fellow, Wayne State University","Lecture / Discussion","""The Dead Stars Society, or Research Alliances with Under-Resourced Institutions""
I became aware that many highschool students in the Detroit area who were interested in pursuing studies in astronomy were first attending community college for two years before transferring to a four-year institution to finish out their degree in the remaining two years. In my own experience as a former community college and subsequent transfer student, I found that it was much more difficult to have access to the same research opportunities and resources as a traditional four year undergraduate student. This is an area where I have always wanted to make a positive change for the community. I finally found the opportunity in 2022, and the Dead Stars Society, an astronomy research group at Henry Ford College in Dearborn, evolved. In the past year, we have had five students join our group, who have collectively analyzed a massive X-ray data-set. We have also received funding to shift gears and focus on analysis of upcoming data from Rubin Observatory/LSST. I would particularly like to discuss what information would be helpful to gain further traction to encourage an expansion of four-year institutions partnering with their local community colleges.",https://events.umich.edu/event/114454,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
109434-21822023,"2023-11-03 10:00:00","2023-11-03 11:00:00","Statistics Department Seminar Series: Daniel McCaffrey, Associate Vice President of Psychometric Analysis and Research, Educational Testing Service","""Daniel McCaffrey Lord Chair in Measurement & Statistics Educational Testing Service""","Workshop / Seminar","Abstract: Currently, 49 states in the U.S. measure student achievement growth as part of their statewide elementary and secondary school student-testing programs and for accountability for districts, schools, or educators. These systems use the average of individual students’ growth for all the students in a district, school, or educator’s class. Averaging growth measures for schools, districts or educators with few students can result in substantial year-to-year fluctuations. We proposed smoothing the aggregate growth measures across time using the Empirical Best Linear Prediction (EBLP) to improve the accuracy and, in turn, stability of the aggregate growth measures. I will discuss the implementation of EBLP for aggregate student achievement growth including the statistical models and estimation methods. I will also discuss the results of applying the method to data in two states.
https://www.linkedin.com/in/dan-mccaffrey-1654809/",https://events.umich.edu/event/109434,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
111918-21827918,"2023-11-06 15:00:00","2023-11-06 16:00:00","HEP-Astro Seminar | Searching for New Physics with IceCube Tracks","John Hardin (MIT)","Workshop / Seminar","IceCube is a neutrino telescope built into the ice at the south pole. IceCube is sensitive to tracks as produced by charged current interactions from muon Neutrinos and cascades produced by other flavors and the neutral current. Due to recent machine-learning-based advances in reconstruction, the precision of the pointing and background rejection have improved significantly, and IceCube has been able to detect neutrino emission from the Galactic Plane. Localized emission opens up a wide variety of new physics searches, many based on astrophysical flavor ratios. IceCube as a detector, the recent Galactic Plane result, and the use of IceCube as a vehicle to detect Beyond the Standard Model Physics are discussed.",https://events.umich.edu/event/111918,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111762-21827548,"2023-11-07 16:00:00","2023-11-07 17:00:00","CM-AMO Seminar | From Dipolar to Rydberg Photonics","Hadiseh Alaeian (Purdue University)","Workshop / Seminar","Strong light-induced interactions between atoms are known to cause nonlinearities at a few-photon level which are crucial for applications in quantum information processing. At densities higher than 1 atom per cubic wavelength, such interactions give rise to density shifts and broadenings, and when confined to less than a wavelength size, such dipolar interaction leads to collective blockade phenomena, which mostly have been studied in the context of strongly interacting Rydberg states.
Here we study these phenomena for low-lying excited atomic states confined in thin atomic clouds that are generated via the pulsed Light-Induced Atomic Desorption (LIAD) technique. For the first few nanoseconds, the transient light-induced dipolar interaction of the low-lying lines of Rubidium leads to shifts and broadenings well beyond the well-known Lorentz-Lorenz limit. In the second experiment, we combine the high densities achievable in thermal atomic vapors with an efficient coupling to a slot waveguide. In contrast to free-space interactions, atoms aligned within the slot exhibit repulsive interactions that are further enhanced by a factor of 8 due to the Purcell effect. The corresponding blueshift of the transition frequency of atoms arranged in the essentially one-dimensional geometry vanishes above the saturation, providing a controllable nonlinearity at the few-photon level.
Towards the end of my talk, I will introduce our novel platform in thin-film cuprous oxide, which allows us to realize strongly interacting Rydberg excitons in a solid-state system that is inherently suitable for scalability and integration. The results of these studies pave the way towards a robust scalable platform for quantum nonlinear chiral optics and all-optical quantum information processing in an integrable and scalable platform, and potentially at elevated temperatures.",https://events.umich.edu/event/111762,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
114230-21832525,"2023-11-07 18:30:00","2023-11-07 20:30:00","The Future of EVs & Michigan: Going Electric is Just the Start",,Presentation,"Join Mighty Earth and the University of Michigan Sierra Club Chapter on November 7th from 6:30-8:30 PM @340 West Hall at a panel to explore General Motors' material supply chain and its negative effects on communities and the environment in Michigan and across the globe. The transition to electric vehicles (EVs) represents a huge opportunity to cut tailpipe emissions and address high-carbon materials used to build cars like steel and aluminum which represent 10% of annual greenhouse gases (GHGs). Speakers will explore the local and international impacts of GM’s material supply chain and provide insight from frontline communities living with the economic, health, and environmental impacts of the automaker’s material supply chain.
Why?
GM is a global leader in the automobile industry and thus uniquely positioned to set the industry standard for supply chain decarbonization and respect for human rights and the environment. In 2021 GM launched its campaign, ‘Everybody In’, to document the company’s transition to EVs and carbon neutrality by 2040. However, since announcing these lofty targets, GM has taken little action to meet these goals. Further, GM has named Cleveland Cliffs its “supplier of the year” for six consecutive years, despite that Cleveland Cliffs have been linked to polluting the Dearborn, Michigan community causing many health concerns among its inhabitants, and recently agreed to pay $3 million in fines for dumpingarsenic and cyanide into Lake Michigan.
BEVERAGES AND SNACKS will be served at 6:30PM and the panel will begin at 7PM.",https://events.umich.edu/event/114230,"West Hall",340,"West Hall",,"Activism
Food
Free
Social Impact
Sustainability","Sierra Club at the University of Michigan"
111688-21827420,"2023-11-08 15:00:00","2023-11-08 16:00:00","CANCELLED - Department Colloquium | Quantum Simulations for Quantum Technologies","Giulia Galli (University of Chicago and Argonne National Laboratory)","Workshop / Seminar","In this talk, I will discuss theoretical and computational strategies based on quantum mechanical calculations, aimed at predicting the physical properties of condensed and molecular systems suitable for the development of quantum technologies. Specifically, I will present results for spin defects in two- and three-dimensional semiconductors and insulators, obtained using both classical and near-term quantum computers, and I will discuss several predictions of complex oxides’ properties for neuromorphic applications.",https://events.umich.edu/event/111688,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
114723-21833357,"2023-11-09 15:30:00","2023-11-09 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Kristen McQuinn, Assistant Professor, Rutgers University","Lecture / Discussion","""Resolved Stellar Populations Studies with the Hubble and James Webb Space Telescopes""
The study of resolved stellar populations in nearby galaxies was transformed by the high sensitivity and spatial resolution of the Hubble Space Telescope (HST), and is now being transformed again with the more powerful James Webb Space Telescope (JWST). The results have far-reaching impacts ranging from providing the most detailed and quantitative measures of the star formation histories of low-mass galaxies and insights into their growth across cosmic timescales, to determining precise distances to galaxies throughout the Local Volume which place galaxy properties on an absolute scale and are essential inputs for measuring of the local value of the Hubble Constant.
In this talk, I will (i) highlight recent results from resolved star studies on very low-mass galaxies with HST data, (ii) present the first star formation history of a galaxy with JWST data alongside a comparison to HST data of the same field, and (iii) introduce new tip of the giant branch (TRGB) distance calibrations derived from HST infrared data and JWST data on nearby galaxies, the latter of which paves the way for a JWST-based measure of the Hubble Constant.",https://events.umich.edu/event/114723,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
115074-21834014,"2023-11-09 18:00:00","2023-11-09 19:00:00","SAS Grad Student Panel",,"Reception / Open House","Come hear from current U-M astronomy graduate students! Ask about applications, choosing a program, grad school culture, and more! Pizza will be provided.",https://events.umich.edu/event/115074,"West Hall",411,"West Hall",,"Astronomy
astrophysics
Education
Free
Graduate School
Graduate Students
Science
space science
Student Org","Student Astronomical Society"
109435-21822024,"2023-11-10 10:00:00","2023-11-10 11:00:00","Statistics Department Seminar Series: Yufeng Liu, Professor, Department of Statistics, Operations Research, Genetics, and Biostatistics, University of North Carolina at Chapel Hill","""Statistical Significance of Clustering for High Dimensional Data""","Workshop / Seminar","Abstract: Clustering serves as a fundamental tool for exploratory data analysis, but a key challenge lies in determining the reliability of the clusters identified by these methods, differentiating them from artifacts resulting from natural sampling variations. In this talk, I will present statistical significance of clustering (SigClust) as a cluster evaluation tool for high dimensional data. To begin, we define a cluster as data originating from a single Gaussian distribution and frame the assessment of statistical significance of clustering as a formal testing procedure. Addressing the challenge of high-dimensional covariance estimation in SigClust, we employ a combination of invariance principles and a factor analysis model. I'll also discuss an enhanced SigClust using multidimensional scaling (MDS) on dissimilarity matrices. SigClust for hierarchical clustering will be presented as well. Simulations and real data, including cancer subtype analysis, validate SigClust's effectiveness in assessing clustering significance.
https://yfliu.web.unc.edu/",https://events.umich.edu/event/109435,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
114882-21833728,"2023-11-10 15:00:00","2023-11-10 16:00:00","HET Seminar | The Geometry of Electroweak Symmetry Breaking","Nathaniel Craig ( UCSB)","Lecture / Discussion","Effective field theories (EFTs) suffer from a vast redundancy of description, reminiscent of coordinate invariance, that lends itself to a geometric treatment. In this talk I’ll survey recently-developed geometric insights into EFTs of the Standard Model Higgs sector, including invariant distinctions between possible EFTs of the Higgs boson, a new understanding of the connection between EFT geometry and observables, and generalizations of Riemannian field space geometry that encode information about analyticity and unitarity of the EFT. These developments are relevant to ongoing searches at the LHC and sharpen an open question for future colliders: is electroweak symmetry linearly realized by the known particles of the Standard Model?",https://events.umich.edu/event/114882,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics
Science","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
111920-21827920,"2023-11-13 15:00:00","2023-11-13 16:00:00","HEP-Astro Seminar | Unveiling the Universe with Machine Learning: A Cosmological Perspective","Elena Giusarma (Michigan Tech University)","Workshop / Seminar","In the near future, upcoming Large-Scale Structure (LSS) missions, including DESI, eROSITA, Euclid, WFIRST, and LSST, are poised to survey extensive cosmological volumes, collecting terabytes of data that hold the promise of revolutionizing our understanding of cosmological parameters with unparalleled precision. To attain this ambitious goal, it is imperative to maximize the information extracted from this data. Nevertheless, we face two pivotal challenges in achieving optimal cosmological analyses: the development of precise theoretical models within the non-linear regime and the creation of innovative computational techniques to overcome the computational bottlenecks inherent in conventional simulation methods. During this presentation, I will introduce a cutting-edge machine learning (ML) approach tailored to the construction of a deep learning emulator at the field level for cosmological simulations. I will illustrate how the deep learning methodology provides a highly accurate alternative to conventional techniques by directly translating non-standard cosmological simulations, including those involving neutrinos, from standard simulations. This approach holds the potential to generate precise predictions for cosmological fields across a spectrum of input parameters, streamlining the exploration of non standard cosmological scenarios while significantly enhancing efficiency.
In the latter part of the talk, I will also discuss the exciting potential of utilizing deep learning-based approaches to model the connection between the underlying dark matter distributions from N-body simulations and the galaxy distributions derived from full hydrodynamic simulations. This multifaceted approach promises to significantly advance our capabilities in understanding and modeling complex cosmological phenomena.",https://events.umich.edu/event/111920,"West Hall",335,"West Hall",,"Physics
Science","HEP - Astro Seminars
Department of Physics"
111763-21834218,"2023-11-14 16:00:00","2023-11-14 17:00:00","CM-AMO Seminar | Quantum Sensing of Two-Dimensional Magnetism","Chunhui (Rita) Du (Georgia Institute of Technology)","Workshop / Seminar","Two-dimensional (2D) van der Waals crystals with unconventional magnetic and electrical properties have been a rising topic of modern magnetism and spintronics research over the past years. Currently, there is ongoing intense activity to develop and understand this new family of magnetic materials, as well as to create new ones. The success of these efforts relies simultaneously on advances in theory, material synthesis, and development of new, sensitive metrology tools capable of evaluating the key material properties at the unprecedented length scale. Nitrogen-vacancy (NV) centers, optically active atomic spin defects in diamond, are naturally relevant in this context due to their excellent quantum coherence, highly competitive spatial and field sensitivity, and remarkable functionalities over a broad range of experimental conditions. In this talk, I will present our recent work on using NV centers to perform nanoscale quantum sensing and imaging of 2D magnetic quantum matter. Specifically, we have utilized NV centers to visualize the exotic spin properties of layered, topological magnetic materials [1, 2] and moiré magnetism hosted by twisted van der Waals magnets [3], revealing the rich physics underlying exotic spin transport and dynamic behaviors in reduced dimensionality. Lastly, I will also briefly discuss our ongoing efforts on exploring next-generation van der Waals quantum sensing technologies using color centers beyond NVs [4].
References:
1. N. J. McLaughlin et al., Nano Lett. 22, 5810 (2022).
2. N. J. McLaughlin et al., Nano Lett. 21, 7277 (2021).
3. M. Huang et al., Nat. Commun. 14, 5259 (2023).
4. M. Huang et al., Nat. Commun. 13, 5369 (2022).
Short Bio: Chunhui Du is an Assistant Professor of Physics at Georgia Institute of Technology. She received her B.S. in physics from East China Normal University in 2010, and Ph.D. in Physics from The Ohio State University in 2015. She worked as a postdoctoral fellow at Harvard University from 2015 to 2019. Chunhui’s current research focuses on developing color center-based quantum sensing tools to study emergent condensed matter physics. Chunhui Du has received the National Science Foundation (NSF) Career Award (2021), Air Force Office of Scientific Research (AFOSR) Young Investigator Award (2021), Department of Energy (DOE) Early Career Award (2022), Office of Naval Research (ONR) Young Investigator Award (2023), and International Union of Pure and Applied Physics (IUPAP) Early Career Scientist Prize (2022).",https://events.umich.edu/event/111763,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
111690-21827421,"2023-11-15 15:00:00","2023-11-15 16:00:00","Department Colloquium | Quantum circuit and the hierarchy of many-body entanglement","Xie Chen (Caltech)","Workshop / Seminar","Zoom:
https://umich.zoom.us/j/91055802072
Meeting ID: 910 5580 2072
Passcode: 309241
Entanglement in many-body quantum systems is notoriously hard to characterize due to the exponentially many parameters involved to describe the state. On the other hand, we are usually not interested in all the microscopic details of the entanglement pattern but only some of its global features. It turns out, quantum circuits of different levels of complexity provide a useful way to establish a hierarchy among many-body entanglement structures. A circuit of a finite depth generates only short range entanglement which is in the same gapped phase as an unentangled product state. A linear depth circuit on the other hand can lead to chaos beyond thermal equilibrium. In this talk, we discuss how to reach the interesting regime in between that contains nontrivial gapped orders. This is achieved using the Sequential Quantum Circuit — a circuit of linear depth but with each layer acting only on one subregion in the system. We discuss how the Sequential Quantum Circuit can be used to generate nontrivial gapped states with long range correlation or long range entanglement, perform renormalization group transformation in foliated fracton order, and create defect excitations inside the bulk of a higher dimensional topological state.",https://events.umich.edu/event/111690,"West Hall",340,"West Hall",,"Physics
Science","Department Colloquia
Department of Physics"
115068-21834013,"2023-11-16 15:30:00","2023-11-16 16:20:00","Department of Astronomy 2023-2024 Colloquium Series Presents:","Dr. Alexander Gagliano, Postdoctoral Fellow, Institute for AI & Fundamental Interactions MIT, Harvard, Northeastern, Tufts Universities","Lecture / Discussion","""The Next Generation of Real-Time Transient Science with Petabyte-Scale Observatories""
Supernovae sit at the nexus of multiple areas of astrophysics: they reveal the nature of the Universe's expansion, the formation of heavy elements, and the final stages of stellar evolution. Starting in 2026, the Vera C. Rubin Observatory will find thousands of supernovae every night, dwarfing current samples and ushering in a new era of unprecedented discovery. In this talk, I will outline current efforts to rapidly characterize new events from this massive data stream. I will highlight some classification techniques that focus on the environment, taking advantage of correlations between supernovae and the galaxies where they occur, and discuss the major open questions that these algorithms will clarify in the coming decade.",https://events.umich.edu/event/115068,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
115169-21834131,"2023-11-17 09:30:00","2023-11-17 10:20:00","Department of Astronomy 2023-2024 DEI Series Presents:","Dr. Alexander Gagliano, Postdoctoral Fellow, Institute for AI & Fundamental Interactions MIT, Harvard, Northeastern, Tufts Universities","Lecture / Discussion","""The Burgeoning Role of Sonification in Astrophysics""
The inherently visual nature of astronomical research provides a wealth of material for both pedagogy and public outreach. By communicating novel findings exclusively through this medium, however, we miss out on a valuable opportunity to engage a diverse audience across multiple axes of instruction. In this talk, I will discuss the growing role that sonification (representing data aurally) plays in astrophysics. I will introduce several pioneering sound-based astronomy efforts and use these to motivate astro[sound]bites, a graduate-student-led astronomy podcast that regularly uses sonification. Now in its fourth year, astro[sound]bites has published over 81 episodes across multiple platforms, totaling 21,000+ downloads from 70 different countries. I will discuss the evolution of astro[sound]bites from its inception, highlight some lessons learned, and end with a demonstration of how you can sonify your own data.",https://events.umich.edu/event/115169,"West Hall",411,"West Hall",,"astronomy
astrophysics","Department of Astronomy
Michigan Institute for Research in Astrophysics"
114909-21833775,"2023-11-17 10:00:00","2023-11-17 11:00:00","Department Seminar Seminar Series: Katherine Brumberg, PhD Candidate, Department of Statistics and Data Science, Wharton School of the University of Pennsylvania.","""Optimal Stratification to Address Selection Bias in Observational Studies""","Workshop / Seminar","Abstract:
Randomized controlled trials are the gold standard for determining a treatment effect. However, they are oftentimes too costly, infeasible, or unethical to carry out. In such situations, we turn to observational studies, where the treatment assignment is not randomized. This results in selection bias, leading to incomparable treatment and control groups. One of the most common techniques to address this is propensity score stratification, where we form strata that contain both treated and control individuals who look similar initially so that we can calculate a treatment effect within each stratum. However, propensity score stratification may leave residual imbalances in the covariate distributions between the treated and control groups. Our new technique of optimal refinement addresses this by splitting each propensity score stratum in two in such a way that optimizes the resulting covariate balance.
In this talk, we will start by examining the performance of propensity score stratification and then will move to discussing our new technique of optimal refinement. We will first carefully define the objective as an integer program. Because solving integer programs is often computationally intractable, we will use randomized rounding, an approximation algorithm, to obtain a provably good solution. We will look at the performance of this method both in simulations and via a real-world example studying the effect of right heart catheterization on 30-day mortality.
https://kbrumberg.com/",https://events.umich.edu/event/114909,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Graduate Seminar Series"
111202-21826217,"2023-11-17 15:00:00","2023-11-17 16:00:00","HET Seminar | Correlation functions in TT*-deformed conformal field theories","Ofer Aharony (Weizmann/IAS)","Lecture / Discussion","I will begin by reviewing the movitations for studying the TT* deformation of two dimensional field theories, the original formulation of this deformation, and its formulation in terms of Jackiw-Teitelboim gravity. Then I will discuss how to compute correlation functions of local operators using this formulation, in which the position of the operators is defined using the dynamical coordinates of the formalism. I will focus on the large-momentum behavior of the two-point function when the undeformed theory is a conformal field theory. The main result (based on 2304.14091) is that for momentum q it is given by |q|^{-q^2 t/\pi}, where t is the deformation parameter. Interestingly, the sign of the exponent is different than previous computations which resummed the small momentum expansion. The decay at large momentum manifests the non-locality of the theory, which also appears through the fact that operators with different momentum require a different multiplicative renormalization, and that the large-momentum behavior of the correlation function on the torus is different from the behavior mentioned above on the plane.",https://events.umich.edu/event/111202,"West Hall",335,"West Hall",,"High Energy Theory Seminar
Physics","Leinweber Center for Theoretical Physics
Department of Physics
HET Seminars
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics High Energy Theory Seminars"
115342-21834477,"2023-11-27 11:30:00","2023-11-27 12:30:00","Special CM-AMO Seminar | The Electron-Phonon Problem Revisited","Steven Kivelson (Stanford University)","Workshop / Seminar","Zoom information:
https://umich.zoom.us/j/95485195985 (Passcode: CMAMO)
Short-bio: Professor Steven Kivelson is a distinguished theoretical physicist celebrated for his pivotal contributions to various facets of condensed matter physics notably in the domains of quantum spin liquids high-temperature superconductivity and various strongly-correlated many-body systems. The profound impact of his research has earned him widespread acclaim marked by his election to the American Academy of Arts and Sciences in 2001, the National Academy of Sciences in 2010, and the prestigious Bardeen Prize, conferred by the University of Illinois at Urbana–Champaign in 2012.",https://events.umich.edu/event/115342,"West Hall",340,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
110979-21825955,"2023-11-27 14:00:00","2023-11-27 17:00:00","MICDE DISCOVER Mini-Symposium",,"Conference / Symposium","The Women in Computational Science Symposium is the inaugural event for the MICDE's DISCOVER (Diversity and Innovation in Scientific Computing: Opportunities for Valuing Exploration and Representation) mini-symposium series. This mini-symposium provides a unique opportunity to delve into the pioneering research conducted by women in computational science while also gaining insight into their personal experiences and the challenges they face as researchers.
This year's Women in Computational Science Symposium features:
Katrin Heitmann, as a keynote speaker
Clare Boothe Luce Fellows: Liz Livingston and Jessica Conrad
WISE (Women in Science and Engineering) University of Michigan
Panel discussion on navigating scientific careers",https://events.umich.edu/event/110979,"West Hall",340,"West Hall",,"Discover
Micde
Micde Seminar","Michigan Institute for Computational Discovery and Engineering
Department of Astronomy
Department of Physics"
115277-21834370,"2023-11-28 16:00:00","2023-11-28 17:00:00","CM-AMO Seminar | N-point van Hove singularity origin of the Hidden Order phase of URu2Si2","Jonathan Denlinger (Lawrence Berkeley National Laboratory)","Workshop / Seminar","The 5f heavy fermion system of URu2Si2 is famous for an unconventional “hidden order” (HO) phase transition at T0=17.5K that has been a topic of study for 35 years. A new model is proposed for the underlying physics to be the existence of a van Hove singularity saddle-band dispersion at the Brillouin zone N-point that is only a few meV below the Fermi level, and thus thermally active at T0. The new model, based on temperature-dependent angle resolved photoemission (ARPES) measurements in comparison to DMFT electronic structure calculations [1], is further confirmed by additional ARPES observation of the N-point spectral and dichroic changes for various chemically doped phases with different ferromagnetic, antiferromagnetic or non-magnetic ground states.
[1] J. D. Denlinger et al., Electron. Struct. 4, 013001 (2022).",https://events.umich.edu/event/115277,"West Hall",335,"West Hall",,"Physics
Science","CM-AMO Seminars
Department of Physics"
114908-21833774,"2023-11-28 16:00:00","2023-11-28 17:00:00","Statistics Department Seminar Series: Yun Yang, Associate Professor, Department of Statistics, University of Illinois Urbana-Champaign.","""Generative Models for Implicit Distribution Estimation: a Statistical Perspective""","Workshop / Seminar","Abstract: The estimation of distributions of complex objects from high-dimensional data with low-dimensional structures is an important topic in statistics and machine learning. Modern generative modeling techniques accomplish this by encoding and decoding data to generate new, realistic synthetic data objects, including images and texts. A key aspect of these models is the extraction of low-dimensional latent features, assuming the data lies on a low-dimensional manifold. Our study develops a minimax framework for distribution estimation on unknown submanifolds, incorporating smoothness assumptions on both the target distribution and the manifold. Through the perspective of minimax rates, we examine some existing popular generative models, such as variational autoencoders, generative adversarial networks, and score-based generative models. By analyzing their theoretical properties, we characterize their statistical capabilities in implicit distribution estimation and identify certain limitations that could lead to potential improvements.
https://sites.google.com/site/yunyangstat/",https://events.umich.edu/event/114908,"West Hall",340,"West Hall",,seminar,"Department of Statistics
Department of Statistics Seminar Series"
115227-21834217,"2023-11-28 18:00:00","2023-11-28 20:00:00","Interfaith Panel on Sustainability",,"Lecture / Discussion","Join the University of Michigan Sierra Club Chapter on November 28th from 6:00-8:00 PM to learn about the intersections between religion and sustainability. Representatives from Hillel, the Muslim community, the Campus Chapel, and Buddhism at the University of Michigan will be coming to speak about their respective faiths and how sustainability is ingrained in their mission and traditions. Location details will be sent out closer to the event.",https://events.umich.edu/event/115227,"West Hall",340,"West Hall",,"Buddhism
christianity
Environment
Judaism
Muslim
Religious
Sustainability","Sierra Club at the University of Michigan
Campus Chapel
Michigan Hillel"