Identifier,"Start Date / Time","End Date / Time",Title,Subtitle,Type,Description,Permalink,"Building Name",Room,"Location Name",Cost,Tags,Sponsors
112630-21829205,"2023-11-28 14:30:00","2023-11-28 15:45:00","RTG Number Theory: Motivic sheaves on affine flag varieties","Robert Cass","Workshop / Seminar","Abstract: In this talk I will discuss a categorification of integral generic Hecke algebras using motivic sheaves on affine flag varieties. This eliminates the dependence on the chosen cohomology theory, such as l-adic or Betti cohomology, in previous works. At the unramified level this amounts to a motivic version of the geometric Satake equivalence. On the other extreme, at the Iwahori level we construct a motivic version of Gaitsgory's central functor. This is joint work with T. van den Hove and J. Scholbach.",https://events.umich.edu/event/112630,"East Hall",4096,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
109666-21822627,"2023-11-28 16:00:00","2023-11-28 17:00:00","Colloquium Series Seminar: Non-abelian Hodge theory and the P=W conjecture","Junliang Shen (Yale University)","Lecture / Discussion","Non-abelian Hodge theory relates topological and algebro-geometric objects associated to a compact Riemann surface. More precisely, complex representations of the fundamental group are in correspondence with algebraic vector bundles, equipped with an extra structure called a Higgs field. This yields a transcendental matching between two very different moduli spaces: the character variety (parametrizing representations of the fundamental group) and the Hitchin moduli space (parametrizing Higgs bundles). In 2010, de Cataldo, Hausel, and Migliorini proposed the P=W conjecture, which links precisely the topology of the Hitchin integrable system and the Hodge theory of the character variety. I will introduce the conjecture, review its recent proofs, and discuss how the geometry hidden behind the P=W phenomenon is connected to other branches of mathematics.",https://events.umich.edu/event/109666,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
115471-21834872,"2023-11-28 17:00:00","2023-11-28 18:00:00","Spin glass models and order of fluctuations","Han Le","Workshop / Seminar","Free energy is an important quantity in the study of spin glasses. Results for many spin models show that free energy, as a random variable, behaves differently in low versus high temperature regimes. In this talk, we discuss the low temperature regime. In particular, we will consider an upper bound argument for the order of fluctuations of free energy in the Ising SK model.",https://events.umich.edu/event/115471,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
115473-21834873,"2023-11-29 11:00:00","2023-11-29 12:00:00","Rational duality groups and the Cohomology of SL_n(Z)","Urshita Pal",Presentation,"Certain classes of groups, such as the special linear groups over integers, satisfy a (co)homological duality property that allows one to study their rational cohomology groups. I'll discuss a criterion to test when a group satisfies this duality, and see how in the case of SLnZ this comes down to the fact that the Tits building is homotopy equivalent to a wedge of spheres.",https://events.umich.edu/event/115473,"East Hall",4088,"East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
113352-21830783,"2023-11-29 15:00:00","2023-11-29 16:00:00","Student CA Seminar: An Introduction to Group (Co)homology","Urshita Pal","Workshop / Seminar","(Co)homology groups are important algebraic invariants associated to a group G. In this talk we will look at how to define group (co)homology algebraically and topologically, prove the equivalence of the two definitions, and briefly see examples where having both perspectives can help study a group various finiteness properties and duality properties of a group.",https://events.umich.edu/event/113352,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
113076-21829996,"2023-11-29 16:00:00","2023-11-29 17:00:00","Math Undergraduate Seminar: Exploring Ribbon Knots","Max Natonson","Lecture / Discussion",https://www.overleaf.com/read/ggwfrcssvbmq,https://events.umich.edu/event/113076,"East Hall",3096,"East Hall",,Mathematics,"Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
115189-21834158,"2023-11-29 16:00:00","2023-11-29 17:00:00","Michigan Lectures in Algebraic Geometry: New perspectives on the topology of algebraic maps I","Junliang Shen (Yale)","Workshop / Seminar","Given a proper algebraic map f : X--> Y, the decomposition theorem of Beilinson, Bernstein, Deligne, and Gabber provides powerful tools to the study of its topology. This endows the cohomology of X with an extra structure, known as the perverse filtration, which measures the singularities of the map f. In recent years, the decomposition theorem and the induced perverse filtration have been found to share surprising connections to other branches of mathematics; these include non-abelian Hodge theory (the P=W conjecture), enumerative geometry (Donaldson-Thomas and BPS invariants), planar singularities (DAHA, knot invariants), and hyper-Kähler geometries (Hodge modules, motivic techniques). In this lecture series, I will discuss some of these developments. If time permits, open questions will be presented and discussed.",https://events.umich.edu/event/115189,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
115522-21834952,"2023-11-29 16:00:00","2023-11-29 17:00:00","Time-inconsistent mean-field stopping problems: A regularized equilibrium approach","Fengyi Yuan of HK Poly U.","Workshop / Seminar","ABSTRACT: We study the mean-field Markov decision process (MDP) with the centralized stopping under the non-exponential discount. The problem differs fundamentally from most existing studies due to its time-inconsistent natural and also the continuous state space. Unlike many previous studies on time-inconsistent stopping, we are interested in the general discount function without imposing any structural conditions such as “decreasing impatience”. As a result, the study on the relaxed equilibrium becomes necessary as the pure-strategy equilibrium may not exist in general. We use the method of regularization to prove the existence of the relaxed equilibrium, and at the same time provide approximation results of it. We also establish some connections between the mean-field MDP and the N-agent MDP. As a third advantage of the regularization method, we prove that the regularized equilibrium is an $\epsilon$-equilibrium of N-agent problem when $N$ is sufficiently large and the regularization constant $\lambda$ is sufficiently small.",https://events.umich.edu/event/115522,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
115262-21834337,"2023-11-29 16:00:00","2023-11-29 17:00:00","Weekly DCMB / CCMB Seminar featuring Xiaojie Qiu (incoming Assist. Prof. at Stanford)","Towards foundational predictive spatiotemporal modeling of single cells","Lecture / Discussion","Abstract:
Single-cell RNA-seq, together with RNA velocity and metabolic labeling, reveals cellular states and transitions at unprecedented resolution. Fully exploiting these data, however, requires kinetic models capable of unveiling governing regulatory functions. In the first part of my talk, I will introduce an analytical framework dynamo (https://github.com/aristoteleo/dynamo-release) and highlight dynamo's power to overcome fundamental limitations of conventional splicing-based RNA velocity analyses to enable accurate velocity estimations on a metabolically labeled human hematopoiesis scRNA-seq dataset. Furthermore, differential geometry analyses reveal mechanisms driving early megakaryocyte appearance and elucidate asymmetrical regulation within the PU.1-GATA1 circuit. Leveraging the least-action-path method, dynamo accurately predicts drivers of numerous hematopoietic transitions. Finally, in silico perturbations predict cell-fate diversions induced by gene perturbations. Dynamo, thus, represents an important step in advancing quantitative and predictive theories of cell-state transitions. Cells do not live in a vacuum, but in a milieu defined by cell–cell communication that can be quantified via recent advances in spatial transcriptomics. In my second section of my talk, I will talk about Spateo, a general framework for quantitative spatiotemporal modeling of single-cell resolution spatial transcriptomics. Spateo develops a comprehensive framework of cell-cell interaction to reveal spatial effects of niche factors and cell type-specific ligand-receptor interactions. Furthermore, Spateo reconstructs 3D models of whole embryos, and performs 3D morphometric analyses. Lastly, Spateo introduces the concept of ""morphometric vector field"" of cell migrations and integrates spatial differential geometry to unveil regulatory programs underlying various organogenesis patterns of Drosophila and mouse. Thus, Spateo enables the study of the ecology of organs at a molecular level in 3D space, beyond isolated single cells. Moving forward, my lab will try to integrate advances in machine learning and advances in genomics to learn spatially and temporally resolved models of cell fate transition at whole mouse embryo level in 3D space.
https://umich-health.zoom.us/j/93929606089?pwd=SHh6R1FOQm8xMThRemdxTEFMWWpVdz09",https://events.umich.edu/event/115262,"Palmer Commons","Forum Hall","Palmer Commons",,Mathematics,"DCMB Seminar Series"
115191-21834160,"2023-11-30 15:00:00","2023-11-30 16:00:00","Michigan Lectures in Algebraic Geometry: New perspectives of the topology of algebraic maps II","Junliang Shen (Yale)","Workshop / Seminar","Given a proper algebraic map f : X--> Y, the decomposition theorem of Beilinson, Bernstein, Deligne, and Gabber provides powerful tools to the study of its topology. This endows the cohomology of X with an extra structure, known as the perverse filtration, which measures the singularities of the map f. In recent years, the decomposition theorem and the induced perverse filtration have been found to share surprising connections to other branches of mathematics; these include non-abelian Hodge theory (the P=W conjecture), enumerative geometry (Donaldson-Thomas and BPS invariants), planar singularities (DAHA, knot invariants), and hyper-Kähler geometries (Hodge modules, motivic techniques). In this lecture series, I will discuss some of these developments. If time permits, open questions will be presented and discussed.",https://events.umich.edu/event/115191,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
113367-21830823,"2023-11-30 16:00:00","2023-11-30 16:50:00","Student Dyn/Geo/Top: Introduction to Heegaard Floer Homology","Runji Li","Workshop / Seminar","Heegaard Floer Homology is a useful invariant for three manifolds, and it has many variants that can be used to study four dimensional cobordism and knots in three spheres. In this talk I will first introduce Heegaard decomposition and Heegaard diagram and state some basic properties of them. Then, I will make an analogy to the Lagrangian Floer Homology to define the ingredients of the Heegaard Floer Homology. Finally, I will define the hat version of Heegaard Floer chain complex and homology.",https://events.umich.edu/event/113367,"East Hall",2866,"East Hall",,Mathematics,"Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
115468-21834869,"2023-11-30 16:00:00","2023-11-30 17:30:00","Ten Lectures on Schubert Polynomials. Lecture 8: Drift classes","William Fulton (Michigan)","Workshop / Seminar","We show that every Schubert polynomial has a decomposition as a sum of polynomials, each of which is given by a tableau formula. This corresponds to a decomposition of its set of bumpless pipe dreams into a disjoint union of classes we call drift classes. (The vexillary case, studied in the last two lectures, is the case when there is one drift class.)",https://events.umich.edu/event/115468,"East Hall",4096,"East Hall",,Mathematics,"Schubert Seminar - Department of Mathematics
Department of Mathematics"
115235-21834227,"2023-11-30 18:00:00","2023-11-30 19:30:00","Carnegie Mellon Master's of Science in Computational Finance","Director of Admission, Emily Wertz",Presentation,"Learn about Carnegie Mellon's highly-ranked Master's of Science in Computational Finance. Hear from the director of admissions about the program and general graduate school admissions tips. This program is great for those interested in quantitative finance from an academic and professional standpoint.",https://events.umich.edu/event/115235,"West Hall",335,"West Hall",,Mathematics,"Michigan Finance and Mathematics Society"
115476-21834876,"2023-12-01 12:00:00","2023-12-01 13:00:00","NTRG: Automorphic Representations",,"Workshop / Seminar","We will be discussing Getz-Hahn's ""Introduction to Automorphic Representations.""",https://events.umich.edu/event/115476,"East Hall",3088,"East Hall",,Mathematics,"Student Logic and History of Math Seminar - Department of Mathematics
Department of Mathematics"
111344-21826762,"2023-12-01 15:00:00","2023-12-01 16:00:00","AIM Seminar: Intriguing dynamics in a dense cell monolayer","Evgeniy Khain, Oakland University, Department of Physics","Lecture / Discussion","In this talk, we consider an expansion of a dense monolayer of cells: a collective multicellular phenomenon, where cells divide, grow, and maintain contacts with their neighbors. During migration, cells display complex behavior, adjusting both their division rate and their growth after division to the local mechanical environment. Experimental observations show that cells near the edge of the expanding monolayer are larger and move faster than cells deep inside the colony. To explain these observations and describe cell migration patterns, we formulate a spatio-temporal theoretical model for multicellular dynamics in terms of the cell area distribution; the model includes cell growth after division and effective pressure. Numerical simulations of the model predict both the speed of invasion and the width of the outer proliferative rim; these predictions are in a good agreement with experimental observations. Theoretical analysis yields the equation for density of cells and reveals a novel type of propagating front with compact support. The velocity of front propagation (monolayer expansion) is obtained analytically and its dependence on all the relevant parameters is determined.",https://events.umich.edu/event/111344,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
115523-21834951,"2023-12-01 15:00:00","2023-12-01 16:00:00","Singularities of Hypersurfaces","Jonghyun Lee","Workshop / Seminar","It is not hard to appreciate the beauty of singularities when you see their pictures. In this talk, we will describe important invariants of isolated hypersurface singularities, notably the mixed Hodge structure of the Milnor fiber and its corresponding spectrum, with an application to bounding the number of ordinary double points on projective hypersurfaces of fixed dimension and degree.",https://events.umich.edu/event/115523,"East Hall",2866,"East Hall",,Mathematics,"Student Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
113648-21831387,"2023-12-01 16:00:00","2023-12-01 17:00:00","GEOM SEMINAR: On Measures Invariant under Horospherical Subgroups in Rank One Lie Groups","Minju Lee","Workshop / Seminar","Given a positive Laplace eigenfunction on a hyperbolic manifold, there exists a horospherically invariant measure corresponding to it, known as the Burger-Roblin measure. A question attributed to Babillot concerns whether every horospherically invariant measure arises from such a correspondence. In this talk, I will survey previous works where affirmative answers to this question were found and present a new result extending it to a broad class of subgroups in rank one Lie groups. This is joint work with Or Landesberg, Elon Lindenstrauss, and Hee Oh.",https://events.umich.edu/event/113648,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics"
115192-21834161,"2023-12-01 16:00:00","2023-12-01 17:00:00","Michigan Lectures in Algebraic Geometry: New perspectives on the topology of algebraic maps III","Junliang Shen (Yale)","Workshop / Seminar","Given a proper algebraic map f : X--> Y, the decomposition theorem of Beilinson, Bernstein, Deligne, and Gabber provides powerful tools to the study of its topology. This endows the cohomology of X with an extra structure, known as the perverse filtration, which measures the singularities of the map f. In recent years, the decomposition theorem and the induced perverse filtration have been found to share surprising connections to other branches of mathematics; these include non-abelian Hodge theory (the P=W conjecture), enumerative geometry (Donaldson-Thomas and BPS invariants), planar singularities (DAHA, knot invariants), and hyper-Kähler geometries (Hodge modules, motivic techniques). In this lecture series, I will discuss some of these developments. If time permits, open questions will be presented and discussed.",https://events.umich.edu/event/115192,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
115714-21835416,"2023-12-04 16:00:00","2023-12-04 17:00:00","Student Combinatorics: Heronian friezes","Katie Waddle","Workshop / Seminar","In 2020 Sergey Fomin and Linus Setiabrata introduced an algebraic object called a Heronian frieze that is an analogue of the frieze patterns introduced and studied by Coxeter and Conway in the 1970s inspired by the Euclidean geometry of polygon triangulation. This survey talk will start with frieze patterns, discuss classical results about integrality, and draw connections to cluster algebra theory. We will build up to Heronian friezes, including a discussion of the necessary geometric ingredients. We will end with an advertisement for current work on the case in which the polygon lies on a sphere.",https://events.umich.edu/event/115714,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
110615-21825164,"2023-12-04 16:15:00","2023-12-04 17:30:00","Microlocal sheaves and affine Springer fibers","Pablo Boixeda-Alvarez (Yale)","Workshop / Seminar","Abstract: The resolutions of Slodowy slices \tilde S_e are symplectic varieties that contain the Springer fiber (G/B)_e as a Lagrangian subvariety. In joint work with R. Bezrukavnikov, M. McBreen and Z. Yun, we construct analogues of these spaces for homogeneous affine Springer fibers. We further understand the categories of microlocal sheaves in these symplectic spaces supported on the affine Springer fiber as some categories of coherent sheaves.
In this talk I will mostly focus on the case of the homogeneous element ts for s a regular semisimple element and will discuss some relations of these categories with the small quantum group providing a categorification of joint work with R.Bezrukavnikov, P. Shan and E. Vasserot.
I will then mention some recent application of this result to the Breuil-Mezard conjecture by T. Feng and B. Le Hung.",https://events.umich.edu/event/110615,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
112632-21829207,"2023-12-05 14:30:00","2023-12-05 15:45:00","RTG Number Theory: Pseudo-varieties of profinite graphs and spanning trees","Amrita Acharyya (University of Toledo)","Workshop / Seminar","Abstract: We consider pro-C graphs for certain categories of finite graphs. After exploring some general theory, we specalize to a particular pseudo-variety denoted by ε that arises naturally in constructing end point compactifications of connected abstract graphs. We show that any connected secondcountable pro-ε graph has a profinite analogue of spanning tree as in connected abstract graphs. The structure of pro-ε graphs and their fundamental profinite groups are shown to be analogous in certain ways to that of abstract graphs and their fundamental groups.",https://events.umich.edu/event/112632,"East Hall",4096,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
114430-21832864,"2023-12-05 16:00:00","2023-12-05 17:00:00","Colloquium Seminar: Diffusion-based probabilistic flows and low distortion mappings","Dan Mikulincer","Workshop / Seminar","A central question in the field of optimal transport studies optimization problems involving two measures on a common metric space, a source and a target. The goal is to find a mapping from the source to the target, in a way that minimizes distances. A remarkable fact discovered by Caffarelli is that, in some specific cases of interest, the optimal transport maps on a Euclidean metric space are Lipschitz. Lipschitz regularity is a desirable property because it allows for the transfer of analytic properties between measures. This perspective has proven to be widely influential, with applications extending beyond the field of optimal transport.
In this talk, we will further explore transport maps with low distortion. The key point which we shall highlight is that, for low distortion mappings, the optimality conditions mentioned above do not play a major role. Instead of minimizing distances, we will consider a general construction of transport maps based on probabilistic flows, and introduce a set of techniques to analyze their distortion. In particular, we will go beyond the Euclidean setting and consider Riemannian manifolds as well as infinite-dimensional spaces.
We shall also discuss the emerging and intimate connections between our construction and recent advances in algorithms for generative modeling.",https://events.umich.edu/event/114430,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
115720-21835423,"2023-12-05 17:00:00","2023-12-05 18:00:00","Student Analysis: An Introduction to Vorticity and Incompressible Flow","Anthony Chen","Workshop / Seminar","In this talk, I will introduce the concept of vorticity and discuss its central role in the behavior of incompressible fluids, focusing in particular on the role of the Lagrangian viewpoint. Time permitting, we will discuss some well posedness results, including the theorem of Beale-Kato-Majda.",https://events.umich.edu/event/115720,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
109663-21822625,"2023-12-06 16:00:00","2023-12-06 17:30:00","Algebraic geometry seminar: Syzygies of adjoint linear series on projective varieties","Justin Lacini (Princeton)","Workshop / Seminar","Syzygies of algebraic varieties have long been a topic of intense interest among algebraists and geometers alike. Starting with the pioneering work of Mark Green on curves, numerous attempts have been made to extend these results to higher dimensions. Ein and Lazarsfeld proved that if A is a very ample line bundle, then K_X + mA satisfies property N_p for any m>=n+1+p. It has ever since been an open question if the same holds true for A ample and basepoint free. In recent joint work with Purnaprajna Bangere we give a positive answer to this question.",https://events.umich.edu/event/109663,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
115524-21834953,"2023-12-06 16:00:00","2023-12-06 17:00:00","Convergence of the Backward Deep BSDE Method with Applications to Optimal Stopping Problems.","ZImu Zhu of UCSB","Workshop / Seminar","The optimal stopping problem is one of the core problems in financial markets, with broad appli- cations such as pricing American and Bermudan options. The deep BSDE method [Han, Jentzen and E, PNAS, 115(34):8505-8510, 2018] has shown great power in solving high-dimensional forward- backward stochastic differential equations (FBSDEs), and in- spired many applications. However, the method solves backward stochastic differential equations (BSDEs) in a forward manner, which can not be used for optimal stopping prob- lems that in general require running BSDE backwardly. To overcome this difficulty, a recent paper [Wang, Chen, Sudjianto, Liu and Shen, arXiv:1807.06622, 2018] proposed the back- ward deep BSDE method to solve the optimal stopping problem. In this paper, we provide the rigorous theory for the backward deep BSDE method. Specifically, 1. We derive the a posteriori error estimation, i.e., the error of the numerical solution can be bounded by the training loss function; and; 2. We give an upper bound of the loss function, which can be suffi- ciently small subject to universal approximations. We give two numerical examples, which present consistent performance with the proved theory. This is a joint work with C.Gao, S.Gao and R.Hu.",https://events.umich.edu/event/115524,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
115727-21835437,"2023-12-06 16:00:00","2023-12-06 17:20:00","RTG TopGeomDyn Seminar: Anosov representations in restriction to flows","Tianqi Wang","Workshop / Seminar","We introduce the notion of restricted Anosov representations, characterized by their dominated splitting behavior over associated flows, to encompass many non-Anosov representations with good geometric properties, such as Minsky's primitive-stable representations. As a first application, for a closed hyperbolic surface group, we show that the collection of representations which are Anosov in restriction to the simple geodesics flow gives a domain of discontinuity for the mapping class group action (joint with Nicolas Tholozan). Secondly, for a relatively hyperbolic group, we show that a representation being both divergent and Weisman's extended geometrically finite is equivalent to being Anosov in restriction to a flow associated with the boundary extension.",https://events.umich.edu/event/115727,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics"
114673-21833285,"2023-12-06 16:00:00","2023-12-06 17:00:00","Weekly DCMB / CCMB Seminar Series","Keynote: Nathan E. Hudson, PhD, ""Probing the polymerization and structure of a blood clot""","Lecture / Discussion","Abstract:
Heart attack, ischemic stroke, and venous thromboembolism are leading causes of death and disability worldwide and often result from aberrant blood clotting. Fibrin is a hierarchical biomaterial that forms the structural backbone of blood clots during the hemostatic process. Clots form when individual fibrin molecules polymerize into linear fibers which then branch into a 3-D gel at sites of injuries. These fibrin networks trap red blood cells and other vascular constituents during the wound healing process.
Using a suite of biophysical approaches, we probe the multiscale formation and structure of fibrin networks. At the molecular scale we establish that individual fibrin molecules are not rigid but adapt multiple conformations that likely assist in polymerization. At the fiber scale, we quantify the processes that govern gelation. Moreover, we demonstrate that fibers exhibit remarkable elastic properties that enable the clot to hold together, even under high tension. At the network scale we reveal how relative changes in the initial concentrations of blood clot components result in remarkably different gel structures.
Taken together, these results provide a wholistic framework for understanding the mechanisms that that determine blood clot structures and linking alterations in these processes to pathologies.
https://umich-health.zoom.us/j/93929606089?pwd=SHh6R1FOQm8xMThRemdxTEFMWWpVdz09
Research Projects:
Nathan Hudson studies the exciting field of molecular biophysics. Work in the Hudson lab uses techniques including protein engineering, centrifuge force microscopy, FRET and microfluidics to understand how mechanical force regulates biological function. Projects involve measuring the biomechanical properties of blood coagulation proteins and determining the force-depending binding kinetics of adhesion molecules. There are both graduate- and undergraduate-level projects in the lab and numerous students have won awards for their research with Dr. Hudson.",https://events.umich.edu/event/114673,"Palmer Commons","Forum Hall","Palmer Commons",,Mathematics,"DCMB Seminar Series"
115718-21835421,"2023-12-07 16:00:00","2023-12-07 17:30:00","Ten Lectures on Schubert Polynomials: Lecture 9. Type C Schubert Polynomials","William Fulton (UM)","Workshop / Seminar","After finishing our discussion of decomposing Type A Schubert polynomials into sums of drift polynomials, we will introduce the algebra and geometry of Type C Schubert polynomials.",https://events.umich.edu/event/115718,"East Hall",4088,"East Hall",,Mathematics,"Schubert Seminar - Department of Mathematics
Department of Mathematics"
115769-21835489,"2023-12-13 16:00:00","2023-12-13 17:00:00","Bayesian sequential testing and estimation in discrete time","Yuqiong Wang, Uppsala University","Workshop / Seminar","In this talk, I will present two concrete problems related to sequentially testing and estimating an unknown parameter within the exponential family in discrete time, incorporating observation costs within the Bayesian setting. Specifically, we will examine the entire one-parameter exponential family with an arbitrary prior distribution, and, therefore, we will not rely on conjugate priors. These problems can be embedded in Markovian frameworks. In the absence of explicit solutions, we will discuss the properties of the value functions and their implications for the structure of continuation regions. Beyond the obvious statistical applications, I will briefly discuss their relevance in stochastic control problems with learning features. Part of this talk is based on joint work with Erik Ekström.",https://events.umich.edu/event/115769,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
115352-21834562,"2023-12-13 16:00:00","2023-12-13 17:00:00","DCMB / CCMB Weekly Seminar featuring X. Shirley Liu, PhD (Co-founder & CEO of GV20 Therapeutics)","Integrated Genomics and Computation for Cancer Target and Drug Discovery","Lecture / Discussion","Abstract:
Despite the exciting clinical benefits of immune checkpoint inhibitors, only a minority of cancer patients respond to treatment. Addressing resistance to immune checkpoint inhibitors is an urgent unmet need and requires novel approaches for target identification and drug discovery.
GV20 Therapeutics adopts an interdisciplinary approach integrating functional genomics, big data AI, and cancer immunology for cancer target identification and drug discovery. Our platform computationally extracts antibodies from large cohorts of patient tumor RNA-seq profiles and uses AI to pair targets and corresponding antibodies in silico, de novo with speed and scale. We then leverage in-house and public functional genomics and proteomics data to de-risk the AI-identified targets from patient tumors and provide insights on target function before we conduct systematic in vitro and in vivo validation experiments.
We used this approach to discover our lead program, GV20-0251, which is a first-in-class monoclonal antibody against a novel immune checkpoint IGSF8. In multiple syngeneic tumor models, anti-IGSF8 antibody has single-agent efficacy and is synergistic with anti-PD1 in controlling tumor growth, and the safety of GV20-0251 is currently being tested in the clinic. Our efforts represent the beginning of rationally combining genomics and AI to unlock the hidden information from patient tumors to develop cancer therapeutics.
Short Bio:
Dr. X. Shirley Liu is the co-founder and CEO of GV20 Therapeutics, a clinical stage biopharmaceutical company with pioneering technologies in novel target identification and antibody drug discovery in Oncology. Dr. Liu received PhD in Biomedical Informatics and PhD minor in Computer Science from Stanford University in 2002. She has been a Professor of Biostatistics and Computational Biology at the Department of Data Science at Dana-Farber Cancer Institute (DFCI) and Harvard University, until she joined GV20 full-time in 2022. Her research work focused on algorithm development and data integration modeling for translational cancer research. She has published over 270 papers and has an H-index of 117. Dr. Liu is a fellow of the International Society of Computational Biology (ISCB), American Institute for Medical and Biological Engineering (AIMBE) and was a Breast Cancer Research Foundation Investigator (2017-2021). She is a recipient of the Sloan Research Fellowship (2008), Weitzman Outstanding Early Career Investigator Award from the Endocrine Society (2016), ISCB Innovator Award (2020), and the Benjamin Franklin Award for Open Access in the Life Sciences (2020). Her lab has mentored 27 PhD and postdoctoral trainees to independent academic careers.
https://umich-health.zoom.us/j/93929606089?pwd=SHh6R1FOQm8xMThRemdxTEFMWWpVdz09",https://events.umich.edu/event/115352,"Palmer Commons","Forum Hall","Palmer Commons",,Mathematics,"DCMB Seminar Series"
115724-21835432,"2023-12-13 16:00:00","2023-12-13 18:00:00","GeomTopDyn Seminar: Images of algebraic groups and mixing properties.","Elyasheev Leibtag (Weizman)","Workshop / Seminar","Let G be an algebraic group over a local field.
We will show that generally the image of G under an arbitrary continuous homomorphism into a (Hausdorff) topological group is closed. We will show how mixing properties of unitary representations follow from this topological property.",https://events.umich.edu/event/115724,"Off Campus Location",3866,Virtual,,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics
RTG Seminar on Geometry, Dynamics and Topology - Department of Mathematics"
115948-21835875,"2023-12-14 16:00:00","2023-12-14 17:30:00","Ten Lectures on Schubert Polynomials. Lecture 10: Schubert Polynomials in Types C, B, and D","William Fulton (U. Michigan)","Workshop / Seminar","We'll finish the description of Schubert polynomials in type C, including a relation to those in type A. Finally, and very briefly, we'll mention changes needed in types B and D.",https://events.umich.edu/event/115948,"East Hall",4096,"East Hall",,Mathematics,"Schubert Seminar - Department of Mathematics
Department of Mathematics"
115940-21835868,"2023-12-20 14:00:00","2023-12-20 15:00:00","Free boundary regularity and support propagation in mean field games and optimal transport","Sebastian Munoz","Workshop / Seminar","This talk presents recent findings on the regularity of first-order mean
field game systems with a local coupling. We focus on systems where the initial
density is a compactly supported function on the real line. Our results show that
the solution is smooth in regions where the density is strictly positive and that
the density itself is globally continuous. Additionally, the speed of propagation
is determined by the behavior of the cost function for small densities. When the
coupling is entropic, we demonstrate that the support of the density propagates
with infinite speed. On the other hand, when f(m) = mθ with θ > 0, we prove
that the speed of propagation is finite. In this case, we establish that under
a natural non-degeneracy assumption, the free boundary is strictly convex and
enjoys C1,1
regularity. We also establish sharp estimates on the speed of support
propagation and the rate of long-time decay for the density. Our methods are based on analyzing a new elliptic equation satisfied by the flow of optimal trajectories. The results also apply to mean field planning problems, characterizing the structure of minimizers of a class of optimal transport problems with congestion.",https://events.umich.edu/event/115940,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
115861-21835756,"2023-12-20 16:00:00","2023-12-20 17:00:00","Convergence rate of LQG mean field games with common noise","Jiamin Jian, WPI","Workshop / Seminar","his work focuses on exploring the convergence properties of a generic player’s trajectory and empirical measures in an N-player Linear-Quadratic-Gaussian Nash game, where Brownian motion serves as the common noise. The study establishes three distinct convergence rates concerning the representative player and empirical measure. To investigate the convergence, the methodology relies on a specific decomposition of the equilibrium path in the N-player game and utilizes the associated Mean Field Game framework. It is a joint work with Prof. Qingshuo Song and Dr. Jiaxuan Ye.",https://events.umich.edu/event/115861,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
116398-21836721,"2023-12-21 15:00:00","2023-12-21 16:00:00","Combinatorics seminar -- Title TBA","Grant Barkley, Harvard University","Workshop / Seminar",TBA,https://events.umich.edu/event/116398,,4096,,,Mathematics,"Combinatorics Seminar - Department of Mathematics"
114760-21833575,"2024-01-12 15:00:00","2024-01-12 16:00:00","AIM Seminar: Randomized matrix decompositions for faster scientific computing","Robert Webber, Caltech","Lecture / Discussion","Abstract: Traditional numerical methods based on expensive matrix factorizations struggle with the scale of modern scientific applications. For example, kernel-based algorithms take a data set of size N, form the kernel matrix of size N x N, and then perform an eigendecomposition or inversion at a cost of O(N^3) operations. For data sets of size N >= 10^5, kernel learning is too expensive, straining the limits of personal workstations and even dedicated computing clusters. Randomized iterative methods have emerged as a faster alternative to the classical approaches. These methods combine randomized exploration with information about which matrix structures are important, leading to significant speed gains.
In this talk, I will review recent developments concerning two randomized algorithms. The first is ""randomized block Krylov iteration"", which uses an array of random Gaussian test vectors to probe a large data matrix in order to provide a randomized principal component analysis. Remarkably, this approach works well even when the matrix of interest is not low-rank. The second algorithm is ""randomly pivoted Cholesky decomposition"", which iteratively samples columns from a positive semidefinite matrix using a novelty metric and reconstructs the matrix from the randomly selected columns. Ultimately, both algorithms furnish a randomized approximation of an N x N matrix with a reduced rank k << N, which enables fast inversion or singular value decomposition at a cost of O(N k^2) operations. The speed-up factor from N^3 to N k^2 operations can be 3 million. The newest algorithms achieve this speed-up factor while guaranteeing performance across a broad range of input matrices.
Contact: Shravan Veerapaneni",https://events.umich.edu/event/114760,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
116449-21836847,"2024-01-12 16:00:00","2024-01-12 17:00:00","GEOMETRY SEMINAR. Morse-ness in convex projective geometry","Mitul Islam","Workshop / Seminar","The (Hilbert metric) geometry of properly convex domains generalizes real hyperbolic geometry. This generalization is far from the Riemannian notion of non-positive curvature but they have some intriguing similarities. In coarse geometry, Morse geodesics embody “negatively curved” directions. In this talk, I will explore Morse geodesics in a properly convex domain. I will show that Morse-ness can be characterized entirely using linear algebraic data (i.e. singular values of matrices that track the geodesic). Further, I will discuss how this coarse geometric notion of Morse is closely related to a symmetric space notion of Morse (studied by Kapovich-Leeb-Porti) as well as the smoothness of boundary points. This is joint work with Theodore Weisman.",https://events.umich.edu/event/116449,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics"
115816-21835675,"2024-01-15 16:00:00","2024-01-15 17:00:00","2024 Marjorie Lee Browne Colloquium | Decoding Vision: Unraveling Photoreceptor Vitality & Degeneration through Mathematics","Erika Tatiana Camacho, University of Texas at San Antonio","Lecture / Discussion","This talk will provide a brief overview of my mathematical research in photoreceptor degeneration and vitality at both the cellular and molecular level as well as the interactions and feedback mechanisms within and between these levels. Mathematical modeling has been used to study diverse biological topics ranging from protein folding to cell interactions to interacting populations of humans but has only recently been used to study photoreceptor degeneration, which occurs in age-related maculardegeneration (AMD) and retinitis pigmentosa (RP). There are many different maladies that can result in blindness but the ones that result from photoreceptor degeneration pose the biggest threat as there is no cure. Computer (in silico) experiments in this area have given researchers invaluable insights to mitigate blindness and, in some cases, re-directed experimental research. My mathematical models, often developed in collaboration with experimental researchers and/or their data, investigate experimentally observed photoreceptor death and rescue in retinal degeneration, the complex interrelated metabolic pathways in cones, and the impact of administered neurotrophic factors. Dynamical systems, optimal control, uncertainty and sensitivity analysis together with in silico experiments are used to analyze these systems of nonlinear differential equations. This work highlights the delicate balance of many aspects of the photoreceptor system including the inter-dependent and inter-connected feedback processes modulated by and affecting cone’s metabolism. My work provides a framework for future physiological investigations potentially leading to long-term targeted multi-faceted interventions and therapies.",https://events.umich.edu/event/115816,"East Hall",1324,"East Hall",,Mathematics,"Special Events - Department of Mathematics
Department of Mathematics"
116280-21836554,"2024-01-16 16:00:00","2024-01-16 17:00:00","Colloquium Seminar: Stable or not: Robustness in imaging and scientific machine learning","Rima Alaifari (ETH Zurich)","Workshop / Seminar","Stability is crucial in applications that require deriving solutions from some input data. Classically, the notion of stability describes robustness under small perturbations of the input and regularization is employed to derive solutions from problems that lack this stable dependence.
In this talk, we visit different problems and methods that lack stability in some, probably less classical, sense. First, we discuss a phase retrieval problem which is not uniformly stable. This non-linear inverse problem cannot be tackled by classical regularization and we highlight possible connections between uniqueness and stability of this problem. Next, we take a look at robustness through the lens of adversarial attacks both for image classification and image reconstruction. While it is known that successful attacks can be designed for data-driven methods, we find that also classical regularization methods can be adversarially attacked.
The last part of the talk is devoted to operator learning and its stability with respect to discretizations. We propose a novel concept of neural operators that by-passes aliasing. These Representation equivalent Neural Operators (ReNOs) establish a unique and stable link between operators on infinite-dimensional spaces and their discrete realizations.",https://events.umich.edu/event/116280,"East Hall","EH 1360","East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
117111-21838676,"2024-01-16 16:00:00","2024-01-16 17:30:00","GLNT: Integral period relations and congruence numbers","Jacques Tilouine (Paris 13)","Workshop / Seminar","This is a report of an ongoing work with K. Prasanna. Let p be a prime; inspired by an earlier work by E. Urban and myself which treated the case of the quadratic base change for GL_2, we formulate a conjecture (and establish part of it), in the case of the transfer from GSp(4) to GL(4),
of a cohomological cuspidal representation \pi, relating the integral periods of \pi and those of its transfer. The proof involves special values of adjoint automorphic L functions and their interpretation as congruence numbers. It seems it can be generalized to several other transfers. It has also consequences for the Bloch-Kato conjecture at p.",https://events.umich.edu/event/117111,"East Hall",5822,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
117084-21838619,"2024-01-16 17:00:00","2024-01-16 18:00:00","Student Analysis Seminar: Planning Meeting + Snack Time!",,"Workshop / Seminar","In this planning meeting, we'll discuss logistics, possible talk ideas, and set up a schedule for speakers this semester. Students in any area of study are welcome to join, and first-year graduate students are especially encouraged to join!
After we finish, we'll have Snack Time! Stop by to chat and eat some food. You are encouraged to bring some snacks to share!",https://events.umich.edu/event/117084,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
117199-21838825,"2024-01-17 11:00:00","2024-01-17 12:00:00","Geometry of polynomial representations (part two)","Andrew Snowden (Michigan)",Presentation,"In this talk I will explain some deeper properties of GL-varieties: in particular, I will explain how to construct curves, which is both important and difficult. I will make this as self-contained as possible, so even if you missed (or forgot) part one, it should still make sense.",https://events.umich.edu/event/117199,"East Hall",3254,"East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
108977-21820671,"2024-01-17 12:00:00","2024-01-17 13:00:00","MPSDS JPSM Seminar Series - Using Synergies Between Survey Statistics and Causal Inference to Improve Transportability of Clinical Trials","Michael Elliott - Survey Methodology Program - Michigan Program in Survey and Data Science","Lecture / Discussion","MPSDS Seminar Series
January 17, 2024
12:00 - 1:00 pm
In person, room 1070 Institute for Social Research, and via Zoom. The Zoom call will be locked 10 minutes after the start of the presentation.
Using Synergies Between Survey Statistics and Causal Inference to Improve Transportability of Clinical Trials
Medical researchers have understood for many years that treatment effect estimates obtained from a randomized clinical trial (RCT) -- termed efficacy'' -- can differ from those obtained in a general population -- termed effectiveness''. Only in the past decade has extensive work begun in the statistical literature to bridge this gap using formal quantitative methods. As noted by Rod Little in a letter to the editor in the New Yorker ...randomization in randomized clinical trials concerns the allocation of the treatment, not the selection of individuals for the study. The latter can have an important impact on the average size of a treatment effect,'' with RCT samples often designed, sometimes explicitly, to be more likely to include individuals for whom the treatment may be more effective.
This issue has been various termed generalizability'' or transportability."" Why do we care about transportability? In RCTs we are in the happy situation were treatment assignment is randomized, so confounding due to either observed or unobserved (pre-treatment) covariates is not an issue. But while randomization of treatment eliminates the effect of unobserved confounders, at least net of non-compliance, it does not eliminate the effect of unobserved effect modifiers, which can impact the causal effect of treatment in a population that differs from the RCT sample population. The impact of these interactions on the marginal effect of treatment thus can differ between the RCT population and the final population of interest.
Concurrent with research into transportability has been research into making population inference from non-probability samples. There is a close overlap between these two approaches, particularly with respect to the non-probability inference methods that rely on information from a relevant probability sample of the target population to reduce selection bias effects. When there are relevant censuses or probability samples of the target patient population of interest, these methods can be adapted to transport information from the RCT to the patient population. Because the RCT setting focuses on causal inference, this adaptation involves extensions to estimate counterfactuals. Thus approaches that treat population inference as a missing data problem are a natural fit to connect these two strands of methodological innovation.
In particular, we propose to extend a pseudo-weighting'' methodology from other non-probability settings to a doubly robust'' estimator that treats sampling probabilities or weights as regression covariates to achieve consistent estimation of population quantities. We explore our proposed approach and compare with some standard existing methods in a simulation study to assess the effectiveness of the approach under differing degrees of selection bias and model misspecification, and compare it with results obtained using the RT data only and with existing methods that use inverse probability weights. We apply it to a study of pulmonary artery catheterization in critically ill patients where we believe differences between the trial sample and the larger population might impact overall estimates of treatment effects.",https://events.umich.edu/event/108977,"Off Campus Location","Room 1070, Institute for Social Research",Virtual,,Mathematics,"Michigan Program in Survey and Data Science
Institute for Social Research"
117208-21838829,"2024-01-17 13:00:00","2024-01-17 14:00:00","Student AIM Seminar Planning Meeting",,Meeting,"Hope you had a wonderful winter break and welcome back to another semester. We are excited to kick off the Student AIM Seminar with our first planning meeting this Wednesday, January 17th, from 1-2 PM in East Hall 1372.
Please stop by to let us know about any social/professional event ideas, research topics, or speakers that you'd like us to facilitate for this semester. All are welcome!
We're looking forward to seeing you there!",https://events.umich.edu/event/117208,"East Hall",1372,"East Hall",,Mathematics,"Student AIM Seminar - Department of Mathematics"
116962-21838251,"2024-01-17 15:00:00","2024-01-17 16:00:00","Student CA Seminar: Planning Meeting",,"Workshop / Seminar","Do you have topic suggestions that you want someone to speak about? Do you want to volunteer to give a talk? Are you just curious about what this student commutative algebra seminar is about? Come and plan with us! Grad students (and undergrads & postdocs) interested in Commutative Algebra, and possibly related topics like Algebraic Geometry, Number Theory, Combinatorics, Representation Theory, etc, are especially encouraged to attend! Student CA is a friendly place to learn about interesting topics in commutative algebra, and the talks are intended to be accessible to a broader algebra audience.",https://events.umich.edu/event/116962,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
107790-21816585,"2024-01-17 16:00:00","2024-01-17 17:00:00","2024 Ta-You Wu Lecture in Physics | The Discovery of Pulsars","Professor Dame Jocelyn Bell Burnell (University of Oxford, England, UK)","Workshop / Seminar","Presentation Abstract: A grad student notices something that she cannot explain…it’s not a fault with the equipment…then there’s a second…and yet more…A story from radio astronomy that marks the beginning of pulsar research.
Professor Dame Jocelyn Bell Burnell was the discoverer of the first radio pulsars, one of the most important astronomical discoveries of the 20th Century. She has received numerous awards and honors and is a devoted advocate for women in science.
Please join us for the lecture at 4:00 pm and a reception before the lecture beginning at 3:30 pm. You may find more information on our webpage: https://myumi.ch/xmvm8.
This lecture will also be live-streamed via YouTube at https://youtu.be/KIzhXjmEnaU.",https://events.umich.edu/event/107790,"Rackham Graduate School (Horace H.)","Rackham Amphitheatre","Rackham Graduate School (Horace H.)",,Mathematics,"Department Colloquia
The College of Literature, Science, and the Arts
Department of Astronomy
Department of Physics
Graduate Society of Women Engineers
Association for Women in Science
Science Learning Center
MICHIGAN UNDERGRADUATE STUDENTS OF STATISTICS
The Center for the Study of Complex Systems
Applied Physics
Women in Science and Engineering (WISE) Program
Department of Chemistry
LSA Biophysics
Michigan Institute for Research in Astrophysics
Department of Mathematics
Astronomy Colloquia
Graduate Rackham International
Undergrad Physics Events
Graduate Society of Black Engineers and Scientists
Math Undergraduate Seminar - Department of Mathematics
Leinweber Center for Theoretical Physics Cosmology Astrophysics Seminars"
117022-21838481,"2024-01-17 16:00:00","2024-01-17 17:00:00","Large Deviations for Empirical Measures of Self-Interacting Markov Chains.","Pavlos Zoubouloglou, UNC Chapel Hill","Workshop / Seminar","Let $\Delta^o$ be a finite set and, for each probability measure $m$ on $\Delta^o$, let $G(m)$ be a transition kernel on $\Delta^o$. Consider the sequence $\{X_n\}$ of $\Delta^o$-valued random variables such that, and given $X_0,\ldots,X_n$, the conditional distribution of $X_{n+1}$ is $G(L^{n+1})(X_n,\cdot)$, where $L^{n+1}=\frac{1}{n+1}\sum_{i=0}^{n}\delta_{X_i}$. Under conditions on $G$ we establish a large deviation principle for the sequence $\{L^n\}$. As one application of this result we obtain large deviation asymptotics for the Aldous-Flannery-Palacios (1988) approximation scheme for quasi-stationary distributions of finite state Markov chains. The conditions on $G$ cover other models as well, including certain models with edge or vertex reinforcement.",https://events.umich.edu/event/117022,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
117110-21838675,"2024-01-17 16:00:00","2024-01-17 17:20:00","RTG GeomTopDyn: Measure rigidity theorems in smooth dynamics.","Asaf Katz","Workshop / Seminar","Classifying the invariant measures for a given dynamical system is a fundamental problem.
In the field of homogeneous dynamics, several important theorems give us an essentially complete picture.Moving away from homogeneous dynamics — results are scarcer, mainly due to some profound difficulties carrying out the techniques used in homogeneous dynamics.
A recent development in Teichmuller dynamics — the celebrated magic wand theorem of Eskin–Mirzakhani, gives one such example and actually provides a technique — the factorization method — for proving such results in certain systems.
I will explain how one can implement the factorization method of Eskin–Mirzakhani in smooth dynamics, in order to achieve measure classification of u-Gibbs states for non-integrable Anosov actions. Moreover, I will try to explain some applications of the theorem, including a result of Avila–Crovosier–Eskin–Potrie–Wilkinson–Zhang towards Gogolev’s conjecture on actions on the 3D torus.",https://events.umich.edu/event/117110,"East Hall",3866,"East Hall",,Mathematics,"RTG Seminar on Geometry, Dynamics and Topology - Department of Mathematics
Department of Mathematics"
117069-21838587,"2024-01-18 16:00:00","2024-01-18 16:50:00","Student DGT - Planning Meeting",,"Workshop / Seminar","This seminar welcomes anyone interested in hearing or speaking about topics within or adjacent to geometry, dynamics or topology. In this first meeting, we will plan and decide a talk schedule for this semester.",https://events.umich.edu/event/117069,"East Hall",2866,"East Hall",,Mathematics,"Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
114761-21833576,"2024-01-19 15:00:00","2024-01-19 16:00:00","AIM Seminar: The Heisenberg limit in quantum algorithms and learning","Yu Tong, Caltech","Lecture / Discussion","Abstract: The Heisenberg limit is a fundamental limit imposed by the principles of quantum mechanics. It provides a lower bound of the amount of resources needed to achieve certain precision in an estimation task. Saturating the Heisenberg limit brings practical benefits to quantum algorithms and learning protocols. In this talk I will present two algorithms that saturate the Heisenberg limit in ground state energy estimation and in Hamiltonian learning respectively. No prior knowledge of quantum mechanics or quantum computing is assumed.
The seminar will also be broadcast via Zoom at the link https://umich.zoom.us/j/96021646996
Meeting ID: 960 2164 6996
Passcode: 034405
Contact: Shravan Veerapaneni",https://events.umich.edu/event/114761,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
116408-21836744,"2024-01-19 15:00:00","2024-01-19 16:00:00","Combinatorics seminar -- Formal geometry of affine Coxeter groups","Grant Barkley, Harvard University","Workshop / Seminar","We study formal regions of infinite Coxeter arrangements, which can be identified with biclosed subsets of the associated positive root system, and which are conjectured to be the topes of an oriented matroid on the reflections of the Coxeter group. They organize into a partial order which extends the weak Bruhat order on the group. Recently, we showed in joint work with David Speyer that this poset is a complete lattice when W is an affine Coxeter group, resolving a conjecture of Matthew Dyer for these groups. Focusing on the affine symmetric group (type A tilde), we show that the completely join-irreducible elements of this lattice correspond to shards of its Coxeter arrangement, as is known for finite Coxeter groups. We give a combinatorial description of the shards using cyclic non-crossing arc diagrams. We also show these objects biject with certain modules, called real bricks, over a type A tilde preprojective algebra, and discuss the relationship between the extended weak order and the lattice of torsion classes for this algebra.",https://events.umich.edu/event/116408,"East Hall",4096,"East Hall",,Mathematics,"Combinatorics Seminar - Department of Mathematics"
115269-21834347,"2024-01-19 16:00:00","2024-01-19 17:00:00","Separable homology of graphs and the Whitehead complex","Becky Eastham (Wisconsin)","Workshop / Seminar","We introduce a 1-complex associated with a finite regular cover of the rose and show that it is connected if and only if the fundamental group of the associated cover is generated by elements in a proper free factor of the free group. When the associated cover represents a characteristic subgroup of the free group, the complex admits an action of Out(F_n) by isometries. We then explore the coarse geometry of the 1-complex, showing that every component has infinite diameter, and that the 1-complex associated with the rose is nonhyperbolic. As corollaries, we obtain that the Cayley graph of the free group with the infinite generating set consisting of all primitive elements has infinite diameter and is nonhyperbolic.",https://events.umich.edu/event/115269,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics"
117286-21839118,"2024-01-22 15:15:00","2024-01-22 16:15:00","RTG Number Theory Seminar: Planning Meeting",,"Workshop / Seminar","This is a planning meeting for this semester's RTG Number Theory seminar. We plan to have local speakers give 60-minute research talks followed by discussion. Speakers will be encouraged to share a problem or problems at the end of their talk that can serve as a starting point for discussions and collaborations among participants.
Please email Charlotte (charchan@umich.edu) if you would like to be on our mailing list.
*** Note that this seminar now meets Mondays 3:15p-4:15p ***",https://events.umich.edu/event/117286,"East Hall",3088,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
117604-21839581,"2024-01-22 16:00:00","2024-01-22 17:00:00","Student Combinatorics: Planning Meeting",,"Workshop / Seminar","Please join us for our planning meeting! We will discuss what topics we want to present/hear this semester. There will be a snack.",https://events.umich.edu/event/117604,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
112181-21828568,"2024-01-22 16:15:00","2024-01-22 17:15:00","GLNT: Integer distance sets","Sarah Peluse (UM)","Workshop / Seminar","I'll talk about new joint work with Rachel Greenfeld and Marina Iliopoulou in which we address some classical questions concerning the size and structure of integer distance sets. Our main result is that any integer distance set in the Euclidean plane has all but a very small number of points lying on a single line or circle. From this, we deduce a near-optimal lower bound on the diameter of any non-collinear integer distance set of size n and a strong upper bound on the size of any integer distance set in [-N,N]^2 with no three points on a line and no four points on a circle.",https://events.umich.edu/event/112181,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
113474-21831053,"2024-01-23 16:00:00","2024-01-23 17:00:00","Colloquium Series Seminar: Perverse sheaves and representations of p-adic groups","Charlotte Chan (University of Michigan)","Workshop / Seminar","One of the first basic ideas we all learn is that a continuous function is determined by its values on a dense open subset. In representation theory, this allows us to recognize a representation of a Lie group from an especially well-behaved locus--that of regular semisimple elements. But what if we want to study representations of matrix groups over finite fields? Lusztig's revolutionary idea in the 1980s was to replace the analytic notion of limit in the continuous setting by the algebro-geometric notion of intermediate extension in this discrete setting. I will explain this picture and describe a recent construction of perverse sheaves that give rise to positive-depth supercuspidal representations of p-adic groups. In the simplest nontrivial case, this resolves a 2004 conjecture of Lusztig. This is joint work with R. Bezrukavnikov.",https://events.umich.edu/event/113474,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
113077-21839807,"2024-01-23 16:00:00","2024-01-23 17:00:00","Math Undergraduate Seminar: It’s All A Lie","Abby Hess","Lecture / Discussion","This will be an introductory exploration of the relationships between Lie algebras, Lie groups, and basic representations of such.",https://events.umich.edu/event/113077,"East Hall",B743,"East Hall",,Mathematics,"Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
117598-21839571,"2024-01-23 17:00:00","2024-01-23 18:00:00","Student Analysis Seminar: Optimal Transport","Yuchuan Yang","Workshop / Seminar","This will be a short introduction to the theory of optimal transportation. We will discuss the Monge-Kantorovich problem, the dual problem, and if time permits, the Benamou-Brenier formula.",https://events.umich.edu/event/117598,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
117733-21839896,"2024-01-24 10:00:00","2024-01-24 23:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117023-21838482,"2024-01-24 11:00:00","2024-01-24 12:00:00","Computational Nonlinear Filtering: A Deep Learning Approach","Hongjiang Qian, University of Connecticut","Workshop / Seminar","Given the state of a system is not completely observable, filtering is concerned with state estimation based on partial observations of the system state. It enjoys many applications in the control of partially observed systems, target tracking, signal processing, statistics, and financial engineering. Devoted to the conditional distribution or density, the celebrated results of the Kushner equation and Duncan-Mortensen-Zakai equation produce nonparametric estimations of the conditional distribution/density. Approximating their solutions will suffer the curse of dimensionality. In this talk, we first introduce a new filtering algorithm termed deep filtering based on the deep learning framework. Instead of approximating the conditional distribution or density, we focus on state estimation or conditional mean. We convert the filtering problem to an optimization problem by finding the optimal weights of a deep neural network (DNN). This solves a long-standing (60-year-old) challenging problem in computational nonlinear filtering and has the potential to overcome the curse of dimensionality. Then, we present our work on deep filtering with adaptive learning rates. Besides updating the parameters of the DNN, we also update the learning rates adaptively. Our algorithm is a two-time-scale stochastic gradient descent algorithm. The updating of the learning rates is unsupervised learning. We proved the asymptotic results of our algorithm and achieved error bounds for the parameters of the neural network. Finally, we will present some numerical examples to show the efficiency and robustness of our algorithm. This is based on joint work with Prof. George Yin and Prof. Qing Zhang.",https://events.umich.edu/event/117023,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
117239-21838861,"2024-01-24 11:00:00","2024-01-24 12:00:00","Homological stability for Hurwitz spaces","Zachary Himes (Michigan)",Presentation,"Let G be a finite group and c a conjugacy class of G. Hurwitz spaces are certain spaces built out of the unordered configuration space of the plane and (G, c). I will talk about work of Ellenberg—Venkatesh—Westerland, where they prove that the homology of these spaces stabilize in certain cases. Time permitting, I will also talk about how they apply this stability result to say something about a heuristic in number theory about class groups of quadratic field extensions over the field F_q(t), with q=p^n for p an odd prime.",https://events.umich.edu/event/117239,"East Hall","Pillsbury Room","East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
116026-21836083,"2024-01-24 12:00:00","2024-01-24 13:00:00","MPSDS JPSM Seminar Series - A Novel Methodology for Improving Applications of Modern Predictive Modeling Tools to Linked Data Sets Subject to Mismatch Error","Brady T. West - University of Michigan","Lecture / Discussion","MPSDS JPSM Seminar Series
January 24, 2024
12:00 - 1:00 EST
In person, Room 1070, Institute for Social Research and via Zoom. The Zoom call will be locked 10 minutes after the start of the presentation.
A Novel Methodology for Improving Applications of Modern Predictive Modeling Tools to Linked Data Sets Subject to Mismatch Error
In recent years, the rise of social media platforms such as Twitter/X has provided social scientists with a wealth of user-content data, and there has been renewed interest in the utility of administrative records for increasing survey efficiency. Combining social media data, administrative records, and survey data has the potential to produce a comprehensive source of information for social research. These data are often collected from multiple sources and combined by probabilistic record linkage. For the analysis of these linked data files, advanced machine learning techniques, such as random forests, boosting, and related ensemble methods, have become essential tools for survey methodologists and data scientists. There is, however, a potential pitfall in the widespread application of these techniques to linked data sets that needs more attention. Linkage errors such as mismatch and missed-match errors can distort the true relationships between variables and adversely alter the performance metrics routinely output by predictive modeling techniques, such as variable importance, confusion matrices, RMSE, etc. Thus, the actual predictive performance of these machine-learning techniques may not be realized. In this presentation, I will describe a new general methodology designed to adjust modern predictive modeling techniques for the presence of mismatch errors in linked data sets. The proposed approach, based on mixture modeling, is general enough to accommodate various predictive modeling techniques in a unified fashion. I evaluate the performance of the new methodology with simulations implemented in R. I will conclude with recommendations for future work in this area.
Brady T. West is a Research Professor in the Survey Methodology Program, located within the Survey Research Center at the Institute for Social Research on the University of Michigan-Ann Arbor (U-M) campus. He earned his PhD from the Michigan Program in Survey and Data Science in 2011. Before that, he received an MA in Applied Statistics from the U-M Statistics Department in 2002, being recognized as an Outstanding First-year Applied Masters student, and a BS in Statistics with Highest Honors and Highest Distinction from the U-M Statistics Department in 2001. His current research interests include the implications of measurement error in auxiliary variables and survey paradata for survey estimation, selection bias in surveys, responsive/adaptive survey design, interviewer effects, and multilevel regression models for clustered and longitudinal data. He is the lead author of a book comparing different statistical software packages in terms of their mixed-effects modeling procedures (Linear Mixed Models: A Practical Guide using Statistical Software, Third Edition, Chapman Hall/CRC Press, 2022), and he is a co-author of a second book entitled Applied Survey Data Analysis (with Steven Heeringa and Pat Berglund), the second edition of which was published by CRC Press in June 2017. He was elected as a Fellow of the American Statistical Association in 2022.",https://events.umich.edu/event/116026,"Off Campus Location","Room 1070, Institute for Social Research",Virtual,,Mathematics,"Michigan Program in Survey and Data Science
Institute for Social Research
Survey Research Center"
117612-21839693,"2024-01-24 15:00:00","2024-01-24 16:30:00","Logic Seminar: organizational meeting","Ronnie Chen","Workshop / Seminar","We will decide on a learning seminar topic for the rest of the semester.",https://events.umich.edu/event/117612,,,,,Mathematics,"Logic Seminar - Department of Mathematics
Department of Mathematics"
117315-21839160,"2024-01-24 15:00:00","2024-01-24 16:00:00","Student CA Seminar: p-monomials","Olivia Strahan","Workshop / Seminar","Let Z_(p) be the localization of the integers at some prime ideal (p). Polynomial rings or power series rings in n variables have a natural N^n-multigrading given by multidegree in each of the variables. Over a field, the homogeneous elements under this multigrading are just monomials, but over Z_(p) the homogeneous elements are ""p-monomials"": the product of a monomial with a power of the prime p. Surprisingly, many of the nice computational lemmas from the monomial setting can be replicated for p-monomials. I will discuss the properties of p-monomials and show some examples of rings constructed using p-monomials.",https://events.umich.edu/event/117315,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
116743-21837880,"2024-01-24 16:15:00","2024-01-24 17:15:00","MCAIM Colloquium: On Flows and Diffusions: From the Many-Body Fokker-Planck Equation to Stochastic Interpolants","Nicholas Boffi, New York University","Lecture / Discussion","Given a stochastic differential equation, its corresponding Fokker-Planck equation is generically intractable to solve because its high dimensionality prohibits the application of standard numerical techniques. In this talk, I will exploit an analogy between the Fokker-Planck equation and modern generative models from machine learning to develop an algorithm for its solution in high dimension. The method enables the computation of previously intractable quantities of interest, such as the entropy production rate of active matter systems, which quantifies the magnitude of nonequilibrium effects. I will then highlight how insight from the Fokker-Planck equation facilitates the development of a new class of generative models known as stochastic interpolants, which generalize state of the art diffusion models in several key ways that can be leveraged to improve practical performance. Along the way, I will argue that methods from machine learning offer a compelling solution for many fascinating high-dimensional mathematical problems that are currently out of reach with more traditional computational tools.
Talk will be in-person and on Zoom: https://umich.zoom.us/j/98734707290",https://events.umich.edu/event/116743,"East Hall",1360,"East Hall",,Mathematics,"MCAIM - Department of Mathematics
Department of Mathematics
Michigan Center for Applied and Interdisciplinary Mathematics"
117265-21839056,"2024-01-25 11:30:00","2024-01-25 13:00:00","Inquiry Based Learning (IBL) Lunch",,"Lecture / Discussion","Come talk about teaching with IBL, interactive, and other active teaching methods over lunch!
Bring teaching anecdotes, thoughts, and your lunch. Snacks will be provided.",https://events.umich.edu/event/117265,"East Hall",4866,"East Hall",,Mathematics,"Department of Mathematics
Inquiry Based Learning (IBL) - Department of Mathematics"
117410-21839269,"2024-01-25 16:00:00","2024-01-25 17:30:00","1st order deformations","Benjamin Baily","Workshop / Seminar",TBA,https://events.umich.edu/event/117410,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Learning Seminar - Department of Mathematics
Department of Mathematics"
117288-21839121,"2024-01-25 16:00:00","2024-01-25 17:00:00","Commutative Algebra Seminar: Schmidt rank/strength and the singular locus","Amichai Lampert (UMich)","Workshop / Seminar","The Schmidt rank/strength of a polynomial is an algebraic measure of its non-degeneracy. It has proven very useful for studying questions regarding polynomials of fixed degree in arbitrarily many variables: Schmidt used it to count integer solutions for systems of polynomial equations with rational coefficients, Green and Tao used it to investigate the distribution of values of polynomials over finite fields, and Ananyan and Hochster used it to prove Stillman's conjecture regarding projective dimension of ideals in polynomial rings. A central tool in all these applications is a close relationship between Schmidt rank/strength of a polynomial and a geometric measure of its non-degeneracy - The codimension of the singular locus of the polynomial. I will present a recent result on quantitative bounds for this relationship and discuss some related results and questions.
Joint work with David Kazhdan and Alexander Polishchuk.",https://events.umich.edu/event/117288,"East Hall",3088,"East Hall",,Mathematics,"Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
117608-21839683,"2024-01-25 16:00:00","2024-01-25 16:50:00","Student Dyn/Geo/Top : Lightning Talks",,"Workshop / Seminar","Speakers will give short 5-15 min talks on a topic that they're interested in or want to learn more about, in an environment even more casual than usual",https://events.umich.edu/event/117608,"East Hall",2866,"East Hall",,Mathematics,"Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
116881-21838140,"2024-01-25 18:30:00","2024-01-25 19:00:00","Michigan in Washington Information Session",,Meeting,"Please join us to learn about the Michigan in Washington program and how it can help you achieve your career goals. https://umich.zoom.us/j/96067832605",https://events.umich.edu/event/116881,"1027 E. Huron Building",https://umich.zoom.us/j/96067832605,"1027 E. Huron Building",,Mathematics,"Michigan in Washington Program"
117599-21839572,"2024-01-26 11:15:00","2024-01-26 13:00:00","Student AIM Seminar Lunch Social",,"Social / Informal Gathering","This week, in lieu of our usual seminar, we will be having a lunch social at Slurping Turtle on Friday, January 26th, from 11:15 AM - 1:00 PM! Please join us for a tasty meal and the opportunity to make connections with your fellow applied math enthusiasts.
We will meet at the Joe's Pizza entrance of East Hall by the elevators on the first floor at 11:15 AM, and then walk to Slurping Turtle together. If you plan on attending, please RSVP by Thursday at the following link: https://docs.google.com/spreadsheets/d/1xC5Poz3qCb8xluFnj_VcIeove0r6gEfNITZBdMFubfg/edit#gid=0
Join us as we to attempt to be not only slurping turtles, but also social turtles. Hope to see you there! :)",https://events.umich.edu/event/117599,"Off Campus Location",,"608 E Liberty St, Ann Arbor, MI 48104",,Mathematics,"Student AIM Seminar - Department of Mathematics
Department of Mathematics"
114762-21833577,"2024-01-26 15:00:00","2024-01-26 16:00:00","AIM Seminar: The 3-body problem and a 3-web of Cayley cubics on the 3-sphere","Philip Arathoon, University of Michigan","Lecture / Discussion","Abstract: Finding general solutions to a mechanical system is often far too much to ask. Instead, we look for more tractable, special solutions, such as the equilibria. If the system is symmetric with respect to a group action then we can also look for the relative equilibria; these are solutions contained to a group orbit. Famous examples include the circular solutions of Euler and Lagrange in the 3-body problem. In this talk I will present a new formalism for finding relative equilibria by defining a 'web structure' on shape space, and demonstrate this by classifying the relative equilibria for the spherical 3-body problem.
Contact: AIM Seminar Organizers",https://events.umich.edu/event/114762,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
116413-21836761,"2024-01-26 15:00:00","2024-01-26 16:00:00","Nilsequences as extremal objects in additive combinatorics","Daniel Altman, University of Michigan","Workshop / Seminar","We will begin by introducing the use of higher-order Fourier analysis in additive combinatorics for a general audience. In particular, we will discuss the arithmetic regularity lemma and how it identifies a certain class of arithmetically-structured functions -- nilsequences -- as extremal objects for problems in additive combinatorics. We will then discuss how it has recently come to light that the analysis of nilsequences on certain arithmetic patterns -- those which satisfy a certain algebraic criterion known as the flag condition -- is easier than the general case, and discuss some recent ideas and developments in overcoming the difficulties that arise when the arithmetic pattern of interest is not flag.",https://events.umich.edu/event/116413,"East Hall",4096,"East Hall",,Mathematics,"Combinatorics Seminar - Department of Mathematics"
117609-21839687,"2024-01-26 15:00:00","2024-01-26 16:00:00","The Mumford-Tate conjecture","Calvin Yost-Wolff","Workshop / Seminar",TBA,https://events.umich.edu/event/117609,"East Hall",4088,"East Hall",,Mathematics,"Student Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
117733-21839925,"2024-01-29 12:00:00","2024-01-29 13:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117823-21840074,"2024-01-29 15:00:00","2024-01-29 16:00:00","RTG NT: On Kloosterman sums and representation theory","Elad Zelingher","Workshop / Seminar","Abstract: I will give a quick overview of twisted Kloosterman sums and their associated sheaves defined by Deligne--Katz. Then I will talk about matrix Kloosterman sums defined by Erdélyi--Tóth and about my recent work that reduces these to classical Kloosterman sums and Hall--Littlewood polynomials. In both parts of the talk, I will explain a relation between exterior/symmetric powers of the Kloosterman sheaf and a special value of a Bessel function of a representation of GLn(Fq).",https://events.umich.edu/event/117823,"East Hall",3088,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
117958-21840231,"2024-01-29 16:00:00","2024-01-29 17:00:00","Student Combinatorics: Lightning talks!",Everyone!,"Workshop / Seminar","We will hear short mini talks from anywhere in combinatorics! This semester, the theme is a 'conjecture' you've encountered. Each talk will be 5-15 minutes, with slots available to anyone in attendance.",https://events.umich.edu/event/117958,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
112524-21829078,"2024-01-29 16:15:00","2024-01-29 17:15:00","GLNT: Spin structures on number fields and class group statistics","Artane Siad (Princeton)","Workshop / Seminar","Spin structures determine quadratic refinements of the linking form on the torsion part of homology for closed oriented 3 manifolds and the intersection form on mod 2 homology of closed oriented surfaces. In this talk, I will outline a counterpart of this story for number fields and describe how it explains an anomaly in class group statistics. This is a report on joint work with Akshay Venkatesh.",https://events.umich.edu/event/112524,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
113617-21831239,"2024-01-30 16:00:00","2024-01-30 17:00:00","Colloquium Seminar: Random curves and surfaces","Nina Holden (Courant Institute/NYU)","Workshop / Seminar","How can you sample a surface uniformly at random? A natural approach is to consider a uniformly sampled planar map, which is a model for a discrete surface studied in many branches of both math and physics. When the size of the surface goes to infinity it converges to the continuum random surface known as a Liouville quantum gravity surface, which was originally introduced in the physics literature. We will give an introduction to these objects and present a powerful technique to study them known as conformal welding, where the random fractal curves known as Schramm-Loewner evolutions appear.",https://events.umich.edu/event/113617,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
117695-21839845,"2024-01-30 16:00:00","2024-01-30 17:00:00","Math Undergraduate Seminar: Inverse Semigroups, Morita Equivalence, and More!","Zach Duah","Lecture / Discussion","In this talk we give a brief introduction to the theory of inverse semigroups, a generalization of a group. We then dive into some examples of inverse semigroups before introducing the notion of a local isomorphism between inverse semigroups. Finally, we end off by discussion characterizations of Morita equivalence of certain types of inverse semigroups.",https://events.umich.edu/event/117695,"East Hall",B743,"East Hall",,Mathematics,"Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
117924-21840196,"2024-01-30 17:00:00","2024-01-30 18:00:00","Student Analysis Seminar: Linearized diocotron perturbation (characterization for l ≥ 2 eigenmode)","Shuhong Yang","Workshop / Seminar","The linear stability analysis of the l = 1 diocotron perturbations in a low density single charged plasma confined in a cylindrical Penning trap has been precisely discussed. It has been shown that the l = 1 case admits at most an algebraic instability (no discrete spectra). Now for l ≥ 2 cases, we give a priori estimate for the spectra, and present a characterization for the orders of eigenvalues as poles of the Laplace transform.
Shuhong will bring souvenirs for everyone, to celebrate the upcoming Lunar New Year!",https://events.umich.edu/event/117924,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
117733-21839897,"2024-01-31 10:00:00","2024-01-31 23:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117024-21838483,"2024-01-31 11:00:00","2024-01-31 12:00:00","One barrier and two barrier reflected BSDEs under logarithmic growth and applications","Khalid Ofdil, Ibn Zohr University, Agadir, Morocco","Workshop / Seminar","We deal with the problem of the existence and uniqueness of a solution for onedimensional reflected backward stochastic differential equations with one lower barrier and with two strictly separated barriers when the generator has logarithmic growth y ln |y|| + |z| \sqrt{|ln |z||} in the variables y and z. The terminal value ξ and the obstacle processes (Lt)0≤t≤T and (Ut)0≤t≤T are Lp-integrable for a suitable p > 2. First, we construct the solution for the one barrier case using the localization method, and also the penalization method after we prove the comparison theorem in our setting. Then, we move on to the case of two barriers where we use the concept of local solution to construct a global one. As applications, we broaden the class of functions for which mixed stochastic control problems and mixed zero-sum stochastic differential games admit an optimal strategy",https://events.umich.edu/event/117024,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
117678-21839828,"2024-01-31 11:00:00","2024-01-31 12:00:00","Strength of polynomials over finite fields and equidistribution","Amichai Lampert (Michigan)",Presentation,"Strength is an algebraic measure of nondegeneracy for multivariate polynomials. Motivated by questions in additive combinatorics, Green and Tao proved that polynomials over finite fields with high strength have equidistributed values. This result led to a flurry of various extensions and improvements by many others. I will survey what is known both qualitatively and quantitatively and then introduce an equidistribution result for polynomials with inputs restricted to lie on a variety.
Joint work with Tamar Ziegler.",https://events.umich.edu/event/117678,"East Hall","Pillsbury Room","East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
117926-21840211,"2024-01-31 13:00:00","2024-01-31 14:00:00","Student AIM Seminar: Janus particles: a two-faced tale in microscale fluid dynamics","Kausik Das","Workshop / Seminar","Abstract: We explore spherical Janus particles in which a chemical reaction occurs on one face, depleting a substrate in the suspending fluid and synthesizing a product, while no reaction occurs on the other face. The steady state substrate concentration field is governed by Laplace's equation with mixed boundary conditions. We use the collocation method to obtain numerical solutions to the equation in spherical coordinates and we show that the product concentration field can be expressed in terms of the substrate concentration field. The asymmetry of the reaction gives rise to a slip velocity that causes the particle to move spontaneously in the fluid through a process known as self-diffusiophoresis. Using the Lorentz reciprocal theorem, we obtain the swimming velocity of the particle. The magnitude and direction of propulsion depend on competition between the substrate and product mobilities and diffusivities. We extend the results to Janus particles with arbitrary surface coverage, maximizing the swimming velocity as a function of the size of the reaction site.",https://events.umich.edu/event/117926,"West Hall",120,"West Hall",,Mathematics,"Student AIM Seminar - Department of Mathematics
Department of Mathematics"
117453-21839333,"2024-01-31 15:00:00","2024-01-31 16:00:00","Student CA Seminar: Standard monomial theory","Teresa Yu","Workshop / Seminar","The theory of standard monomials provides a combinatorial approach to studying determinantal rings via a correspondence between products of minors and Young tableaux. In this talk, we will introduce standard monomials and their key properties, including the straightening law. We will then show how to use these properties to study (F-)singularities of determinatal rings.",https://events.umich.edu/event/117453,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
117268-21839059,"2024-01-31 16:00:00","2024-01-31 17:20:00","Algebraic Geometry Seminar: Quartic surfaces in arbitrary characteristic","Igor Dolgachev (Michigan)","Workshop / Seminar","I will review the old and recent results on quartic surfaces and three-dimensional Fano and Calabi-Yau varieties (in characteristic 2), which they define via the double covers of the space branched along a quartic surface. I will give special attention to quartic surfaces over an algebraically closed field of positive characteritic.",https://events.umich.edu/event/117268,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
118159-21840576,"2024-01-31 16:00:00","2024-01-31 17:30:00","Logic Seminar: A crash course in syntactic algebras and Stone-type dualities","Ronnie Chen","Workshop / Seminar","We will explain, via the simple example of propositional logic, the process by which a well-behaved logic with a classical semantics may be given a generalized algebraic semantics, and then turned into a ""syntactic algebra"" forming the universal such semantics, which is then (in the best cases) recoverable from the space of all classical models equipped with suitable ""dual"" structure. Time permitting, we will briefly sketch how similar ideas can be carried over to first-order logic.",https://events.umich.edu/event/118159,"East Hall",5822,"East Hall",,Mathematics,"Logic Seminar - Department of Mathematics
Department of Mathematics"
117452-21839332,"2024-02-01 16:00:00","2024-02-01 17:00:00","Commutative Algebra Seminar: Standard monomial theory modulo Frobenius in characteristic two","Teresa Yu (UMich)","Workshop / Seminar","Over a field of characteristic zero, standard monomial theory and Young tableaux provide a connection between determinantal ideals of polynomial rings and irreducible representation theory of GL_n. In this talk, we present work towards developing an analogous theory over a field of characteristic two by working modulo a Frobenius power. As a result, we obtain modular GL_n-representations whose characters are given by particular truncated Schur polynomials, thus proving a conjecture by Gao-Raicu-VandeBogert in the characteristic two case. This is joint work with Laura Casabella.",https://events.umich.edu/event/117452,"East Hall",3088,"East Hall",,Mathematics,"Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
117415-21839281,"2024-02-01 16:00:00","2024-02-01 17:30:00","Higher Order Deformations","Ben Gould","Workshop / Seminar",TBA,https://events.umich.edu/event/117415,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Learning Seminar - Department of Mathematics
Department of Mathematics"
117919-21840191,"2024-02-01 16:00:00","2024-02-01 17:00:00","Student Dyn/Geo/Top: On the Moving Sofa Problem","Jineon Baek","Workshop / Seminar","Modeling the situation of moving furniture around, the moving sofa problem asks for the maximum area of a planar shape that can move around the corner in an L-shaped hallway of width 1. The problem was posed by Leo Moser in 1966, and the best known lower bound of 2.2195... was proved by Gerver in 1994, by constructing a sofa whose boundary consists of 18 special curves. While it is conjectured that Gerver's sofa attains the maximum area, the best published upper bound of 2.37 was proved by Kallus and Romik in 2018 using computer assistance.
Improving upon the computer-assisted approach of Kallus and Romik, we improve the upper bound to 2.32. Moreover, without any computer assistance, we prove a conceptually new upper bound of $1 + \pi^2/8$ = 2.2337... that is much closer to the lower bound of Gerver, on a large subset of shapes which includes Gerver's sofa. We also discuss the possibility of making the upper bound of 2.2337... unconditional by building upon the approaches of the two results.",https://events.umich.edu/event/117919,"East Hall",2866,"East Hall",,Mathematics,"Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
114763-21833578,"2024-02-02 15:00:00","2024-02-02 16:00:00","AIM Seminar: Small dispersion asymptotics of Benjamin-Ono soliton ensembles","Elliot Blackstone, University of Michigan","Lecture / Discussion","Abstract: The Benjamin-Ono equation is a nonlinear, nonlocal PDE that, roughly speaking, is a model for waves along the interface of two fluids. We discuss some recent results on asymptotics of soliton solutions to the Benjamin-Ono equation and mention a new explicit formula of P. Gérard, along with some implications.
Contact: AIM Seminar Organizers",https://events.umich.edu/event/114763,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
117935-21840207,"2024-02-02 15:00:00","2024-02-02 16:00:00","Derived categories and semiorthogonal decomposition in geometry","Saket Shah","Workshop / Seminar","In this talk, I will review some definitions from the theory of derived categories, especially the notion of a semiorthogonal decomposition. I will give some interesting geometric examples before trying to explain the relation between derived categories, SODs and birational geometry.",https://events.umich.edu/event/117935,"East Hall",4088,"East Hall",,Mathematics,"Student Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
117838-21840092,"2024-02-02 15:00:00","2024-02-02 16:00:00","Incidences and tilings","Sergey Fomin, University of Michigan","Workshop / Seminar","We show that various classical theorems of real/complex linear incidence geometry, such as the theorems of Pappus, Desargues, Möbius, and so on, can be interpreted as special cases of a single ""master theorem"" that involves an arbitrary tiling of a closed oriented surface by quadrilateral tiles. This yields a general mechanism for producing new incidence theorems and generalizing the known ones.
This is joint work with Pavlo Pylyavskyy [arXiv:2305.07728]. The same material was presented last week at the undergraduate Math Club, and in a Math 668 lecture in December.",https://events.umich.edu/event/117838,"East Hall",4096,"East Hall",,Mathematics,"Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
118165-21840584,"2024-02-02 18:00:00","2024-02-02 19:30:00","QuantUM Speaker Series: Quantum Computing and Quantum Gravity","Finn Larsen","Lecture / Discussion","Come join QuantUM for their first speaker series event of the semester! The event is open to all who are interested, and no background knowledge is required. Food will be provided!
Finn Larsen is a theoretical physicist whose long-term research interest is on foundational questions like the beginning of the Universe, and the interior of black holes. In this research area, progress is made by studying simple theoretical models in detail, understanding their principles, and drawing lessons about the structure of space and time. The language of quantum computing and quantum information has proven indispensable for these studies and, by now, there is a fruitful interchange of ideas between these very different research areas.
This talk will focus on ideas in quantum computing, like entanglement and quantum error correction, concluding with how these ideas enter the modern understanding of space and time.",https://events.umich.edu/event/118165,"Michigan League","Koessler Room","Michigan League",,Mathematics,Quant-UM
117733-21839926,"2024-02-05 12:00:00","2024-02-05 13:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117825-21840076,"2024-02-05 15:00:00","2024-02-05 16:00:00","RTG NT: Covers of reductive groups and functoriality","Tasho Kaletha","Workshop / Seminar","Abstract: A key player in the Langlands program is the L-group ^LG of a connected reductive group G over a local or global field. It underpins both pillars of the program: the reciprocity conjecture, which relates automorphic representations of G to Galois representations valued in ^LG, and the functoriality conjecture, which relates automorphic representations of two different groups whose L-groups are related. We will discuss how considerations of functoriality lead to an extension of the concept of L-group to certain non-linear covering groups, and how these can be organized using a new kind of fundamental group associated to G. We will focus on the case of a local field.",https://events.umich.edu/event/117825,"East Hall",3088,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
118361-21840937,"2024-02-05 16:00:00","2024-02-05 17:00:00","Student Combinatorics: Configurations, Graphs and Trees","Urshita Pal","Workshop / Seminar","Configuration Spaces give good prototypical examples to understand the (co)homology of certain groups like braid groups, and the phenomenon of homological stability. In this talk we will explore the topology of configurations of n points on the plane. Through pictures and examples, we will first see how the motion of the particles generates (co)homology classes of these spaces. We will then see how to associate trees and graphs to these classes, and describe a combinatorial pairing between trees and graphs that is analogous to the pairing between cohomology and homology.",https://events.umich.edu/event/118361,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
117814-21840057,"2024-02-06 11:00:00","2024-02-06 12:30:00","Math LCIT Conversation","Meeting of the Math Learning Community on Inclusive Teaching","Lecture / Discussion","This semester we will be discussing the new MAA book by Daniel Reinholz, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester, we will lay the groundwork for our discussions this semester, and start our discussion of Reinholz's book. Loosely, we will aim to use the material through the beginning of chapter 3 as the subject of our discussion (attendees are encouraged to read sections 1.1, 2.3.5-2.4, and 3.1-3.2, or more; but those interested should attend even if they are unable to read in advance).",https://events.umich.edu/event/117814,,4866,,,Mathematics,"Learning Community on Inclusive Teaching in Mathematics - Department of Mathematics
Department of Mathematics"
118362-21840938,"2024-02-06 15:00:00","2024-02-06 16:00:00","Applying Variational Quantum and Quantum-Inspired Algorithms to the Linear Complementarity Problem","Oliver Knitter","Workshop / Seminar","Abstract: Variational quantum algorithms (VQAs) are hybrid quantum–classical algorithms that seek to harness the advantage of quantum computers while simultaneously mitigating the drawbacks of the noisy, intermediate-scale (NISQ) quantum hardware existing today. VQAs have an established theoretical potential, but their ability to effectively solve problems arising from practical applications, and whether this utility can be wholly replicated by quantum-inspired classical algorithms, remains an active area of interest. We present a novel application of both the Variational Quantum Linear Solver (VQLS) and the Variational Neural Linear Solver (VNLS)—an existing VQA for solving systems of linear equations, and its quantum-inspired fully classical counterpart—as the key component within a larger minimum map Newton solver for a complementarity-based rigid body contact model. Using each algorithm, we demonstrate that this solver accurately depicts the dynamics of the model system’s rigid spherical bodies as they collide. These results indicate that quantum and quantum-inspired linear algebra algorithms may provide a satisfactory alternative to standard linear algebra solvers for modeling certain physical systems.",https://events.umich.edu/event/118362,"East Hall",1068,"East Hall",,Mathematics,"Student AIM Seminar - Department of Mathematics
Department of Mathematics"
115964-21835947,"2024-02-06 16:00:00","2024-02-06 17:00:00","Marton's Conjecture, aka the Polynomial Freiman--Ruzsa conjecture","Frederick Manners (UC San Diego)","Workshop / Seminar","A function f(x) is linear if f(x+y)=f(x)+f(y) for all pairs (x,y). Suppose f is ""a bit linear"" -- say, f(x+y)=f(x)+f(y) for 1% of pairs (x,y). What can you say about f? Must it be closely related to an actually linear function? If so, how closely?
This question turns out to be equivalent to asking for good quantitative bounds in the Freiman--Ruzsa theorem, a foundational result in additive combinatorics. Marton gave a formulation, equivalent to the statement above, which she conjectured should have polynomial bounds. I will outline a recent proof of this conjecture.
Joint work with Timothy Gowers, Ben Green and Terence Tao.",https://events.umich.edu/event/115964,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
118443-21841082,"2024-02-06 16:00:00","2024-02-06 17:00:00","Math Undergraduate Seminar","Matthew Anderson and Martha Wolf","Lecture / Discussion","This week's seminar features two talks, namely:
""Optimal Control of a Solar-Powered Racecar"" by Matthew Anderson and
""In-Duck-Tion"" by Martha Wolf",https://events.umich.edu/event/118443,"East Hall",B743,"East Hall",,Mathematics,"Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
117733-21839898,"2024-02-07 10:00:00","2024-02-07 23:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
118233-21840681,"2024-02-07 11:00:00","2024-02-07 12:00:00","Divisibility of character values of the symmetric group","Sarah Peluse (Michigan)",Presentation,"In 2017, Miller computed the character tables of $S_n$ for all $n$ up to $38$ and looked at various statistical properties of the entries. Characters of symmetric groups take only integer values, and, based on his computations, Miller conjectured that almost all entries of the character table of $S_n$ are divisible by any fixed prime power as $n$ tends to infinity. Previously, Sound and I proved this conjecture for any fixed prime. In this talk, I will discuss joint work with Sound that fully resolves it, and mention some related open problems.
**Note regarding location: The Pillsbury room is located on Floor 4M on the Psychology side of East Hall. To get to the room, you enter the Psychology side of East Hall from the Church Street entrance and before you get into the Psych atrium, there is an elevator to your left. Take the elevator to Floor 4M and the elevator opens into the room.**",https://events.umich.edu/event/118233,"East Hall","Pillsbury Room","East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
117428-21839290,"2024-02-07 11:00:00","2024-02-07 12:00:00","Estimating the roughness exponent of stochastic volatility","Xiyue Han","Workshop / Seminar","The roughness exponent of a continuous function $x$ is defined as the number $R\in[0,1]$ for which the $p^{\text{th}}$ variation of $x$ is infinite if $p<1/R$ and zero if $p>1/R$. The roughness exponent characterizes the regularity of financial time series without any probabilistic assumptions and coincides with the traditional Hurst parameter for the sample paths of fractional Brownian motion. It was observed empirically in the seminal work by Gatheral, Jaisson, and Rosenbaum (2018) that the roughness exponent of realized volatility of many financial time series is rather small.
However, one difficulty in the roughness estimation process for the instantaneous volatility $\sigma_t$ is that the instantaneous volatility is observed only indirectly through its antiderivative, namely the quadratic variation $\langle\log S \rangle_t$ of the price trajectory $S_t$. To this end, we introduce a new estimator $\widehat{\mathscr{R}}_n$ for the roughness exponent of the instantaneous volatility that integrates the numerical differentiation of $\langle\log S \rangle_t$ with the estimation of the roughness exponent of the derivative $\sigma_t^2=\frac{d}{dt}\langle\log S \rangle_t$. In this talk, we will demonstrate the consistency of the estimator $\widehat{\mathscr{R}}_n$ for several classes of Gaussian processes, including fractional Brownian motion and fractional Ornstein--Uhlenbeck processes. Furthermore, this talk will highlight the underlying rationale of constructing the estimator $\widehat{\mathscr{R}}_n$, which is based on the robust approximation of the Faber--Schauder coefficients of $\sigma^2_t$.
This talk is based on the joint work with Alexander Schied.",https://events.umich.edu/event/117428,"Off Campus Location",,Virtual,,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
118368-21840943,"2024-02-07 14:30:00","2024-02-07 16:00:00","Learning Seminar in Algebraic Combinatorics: Fans from Toric Varieties","Calvin Yost-Wolff","Workshop / Seminar","This talk will begin building up a dictionary relating geometric properties of toric varieties to combinatorial properties of fans. In particular, we will analyze singularities and compactness of toric varieties. As a by-product of our dictionary, we will see how to form a fan from a normal toric variety.",https://events.umich.edu/event/118368,"East Hall",4088,"East Hall",,Mathematics,"Learning Seminar in Algebraic Combinatorics - Department of Mathematics
Department of Mathematics"
117316-21839163,"2024-02-07 15:00:00","2024-02-07 16:00:00","Student CA Seminar: Graded and local rings","Anna Brosowsky","Workshop / Seminar","A local ring has a unique maximal ideal. A graded ring often has many maximal ideals; however, if it has a unique *homogeneous* maximal ideal then in practice the graded ring will behave like a local ring. We will see some examples of this phenomenon, as well as learn about why it occurs.",https://events.umich.edu/event/117316,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
118297-21840849,"2024-02-07 15:00:00","2024-02-07 15:50:00","Student Number Theory: Additive Combinatorics, Uniformity, and Patterns in Primes","Henry Talbott","Workshop / Seminar","Additive combinatorics provides a powerful framework for understanding additive structure in finite-rank abelian groups. I’ll give an overview of a few of the main techniques in this field, focusing on the structure/randomness dichotomy pioneered by Szemerédi and Gowers. Along the way, I’ll also introduce a close connection between additive combinatorics and ergodic theory, and explain how the transference principle developed by Green and Tao allows additive combinatorics to be applied to questions of additive structure in the set of prime numbers.",https://events.umich.edu/event/118297,"East Hall",5822,"East Hall",,Mathematics,"Student Number Theory Seminar - Department of Mathematics
Department of Mathematics"
115610-21835110,"2024-02-07 16:00:00","2024-02-07 17:30:00","Algebraic Geometry Seminar: Atiyah duality and applications","Toni Annala (IAS)","Workshop / Seminar","In topology, Atiyah duality provides a geometric model for the dual of the suspension spectrum of a smooth manifold. In this talk, we export this into algebraic geometry by proving an analogous claim in the non-A^1-invariant stable motivic homotopy theory of Annala-Hoyois-Iwasa. Besides recovering many Poincaré duality type results, it has quite interesting consequences for the behavior of the A^1-colocalization functor R. Namely, R is a way of turning a cohomology theory into an A^1-invariant one without changing the on smooth projective varieties. Using this observation, we can prove the independence of logarithmic cohomology groups from the choice of good compactification, and that certain cohomology groups are birational invariants.",https://events.umich.edu/event/115610,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
117358-21839212,"2024-02-07 16:00:00","2024-02-07 17:00:00","Department of Computational Medicine & Bioinformatics -- Weekly Seminar","Presenter: Ravi Allada, M.D., ""Why do we sleep? The Circadian and Homeostatic Control of Sleep and Wake""","Lecture / Discussion","Abstract:
Why we sleep remains one of the most enduring mysteries in science. Sleep is homeostatically regulated where the duration of wakefulness drives subsequent sleep. Here we aim to determine how waking experience is sensed to trigger sleep and how sleep restores the brain? How does the circadian clock interact with the sleep homeostat? How does impaired sleep lead to human diseases such as Alzheimer’s disease. Our work makes widespread use of -omics approaches including for the identification of diagnostic biomarkers in human sleep disruption.
Short Bio:
Ravi Allada is the Edward C. Stuntz Distinguished Professor of Neuroscience and Chair of the Department of Neurobiology at Northwestern University. Dr. Allada received his M.D from the University of Michigan and completed a residency in Clinical Pathology at the Brigham and Women’s Hospital. During his training, he was an HHMI-NIH Research Scholar and an HHMI Physician Postdoctoral Fellow, the latter with 2017 Nobel Laureate Michael Rosbash. The Allada laboratory has discovered molecule “gears” of the core circadian clock including a link to neurodegenerative disease as well as pathways linking the core clock to daily rhythms of sleep and wake. His laboratory has also identified molecular processes underlying sleep including those linked to memory processing. His work extends discoveries in flies to mammals including the development of diagnostic biomarker signatures for circadian time and examining the effects of jet lag on athletic performance. His work has been funded by the NIH, DARPA as well as private foundations including a Burroughs Wellcome Career Award and a NARSAD Young Investigator Award. He has served as a member of the NIH Sleep Disorders Research Advisory Board and on the Board of Directors as for the Society for Research on Biological Rhythms and Sleep Research Society.
https://umich-health.zoom.us/j/93929606089?pwd=SHh6R1FOQm8xMThRemdxTEFMWWpVdz09",https://events.umich.edu/event/117358,"Palmer Commons","Forum Hall","Palmer Commons",,Mathematics,"DCMB Seminar Series"
117358-21839254,"2024-02-07 16:00:00","2024-02-07 17:00:00","Department of Computational Medicine & Bioinformatics -- Weekly Seminar","Presenter: Ravi Allada, M.D., ""Why do we sleep? The Circadian and Homeostatic Control of Sleep and Wake""","Lecture / Discussion","Abstract:
Why we sleep remains one of the most enduring mysteries in science. Sleep is homeostatically regulated where the duration of wakefulness drives subsequent sleep. Here we aim to determine how waking experience is sensed to trigger sleep and how sleep restores the brain? How does the circadian clock interact with the sleep homeostat? How does impaired sleep lead to human diseases such as Alzheimer’s disease. Our work makes widespread use of -omics approaches including for the identification of diagnostic biomarkers in human sleep disruption.
Short Bio:
Ravi Allada is the Edward C. Stuntz Distinguished Professor of Neuroscience and Chair of the Department of Neurobiology at Northwestern University. Dr. Allada received his M.D from the University of Michigan and completed a residency in Clinical Pathology at the Brigham and Women’s Hospital. During his training, he was an HHMI-NIH Research Scholar and an HHMI Physician Postdoctoral Fellow, the latter with 2017 Nobel Laureate Michael Rosbash. The Allada laboratory has discovered molecule “gears” of the core circadian clock including a link to neurodegenerative disease as well as pathways linking the core clock to daily rhythms of sleep and wake. His laboratory has also identified molecular processes underlying sleep including those linked to memory processing. His work extends discoveries in flies to mammals including the development of diagnostic biomarker signatures for circadian time and examining the effects of jet lag on athletic performance. His work has been funded by the NIH, DARPA as well as private foundations including a Burroughs Wellcome Career Award and a NARSAD Young Investigator Award. He has served as a member of the NIH Sleep Disorders Research Advisory Board and on the Board of Directors as for the Society for Research on Biological Rhythms and Sleep Research Society.
https://umich-health.zoom.us/j/93929606089?pwd=SHh6R1FOQm8xMThRemdxTEFMWWpVdz09",https://events.umich.edu/event/117358,"North Campus Research Complex Building 520",1122,"North Campus Research Complex Building 520",,Mathematics,"DCMB Seminar Series"
115252-21834274,"2024-02-07 16:00:00","2024-02-07 17:30:00","RTG TopGeomDyn: Introduction to Exponential Mixing Via Additive Combinatorics","Osama Khalil","Workshop / Seminar","This talk will provide background on some of the concepts that will appear in the lecture on Friday. Time permitting, we will introduce some of the key players from the theory of anisotropic Banach spaces, inverse theory in additive combinatorics, Fourier transforms of dynamically defined measures, and the interactions among them. The two lectures will be independent of one another and will not assume background in these topics.",https://events.umich.edu/event/115252,"East Hall",3866,"East Hall",,Mathematics,"RTG Seminar on Geometry, Dynamics and Topology - Department of Mathematics
Department of Mathematics"
118001-21840338,"2024-02-08 11:30:00","2024-02-08 13:00:00","CSCS Seminar | Topological Data Analysis for Shape Comparison","Elizabeth Munch, Department of Computational Mathematics, Science & Engineering; and Mathematics; Michigan State University","Workshop / Seminar","Coffee and snacks will be served. This talk will be recorded for later viewing.
Abstract: The goal of the field of topological data analysis (TDA) is to quantitatively encode and measure shape in data using Algebraic Topology. The available tools encompass both algebraic constructions (such as persistence diagrams and Euler characteristics) as well as graph based representations (such as Reeb graphs, mapper graphs, and merge trees). Applications of TDA have exploded in recent years, finding use in a diverse array of domains including plant biology, neuroscience, mechanical engineering, and many more. This increased interest is due to its now extensive theoretical foundation, and more recently due to the increased availability of more efficient algorithms and software making TDA pipelines more readily accessible to domain scientists. In this talk, we will review some of the tools available with a particular focus on encoding embedded shapes in d-dimensional Euclidean space (with most of our applications living in the setting of d=2 or 3), and for creating metrics between these representations to allow for access to tools such as statistics and machine learning.
Bio: Elizabeth Munch is an Associate Professor at Michigan State University with a primary appointment in the Department of Computational Mathematics, Science, and Engineering and a secondary appointment in the Department of Mathematics. Her research specializes in Applied Topology and Topological Data Analysis. Liz received her PhD from the Department of Mathematics at Duke University in May 2013. Prior to joining the faculty of Michigan State University, she was an Assistant Professor in the Department of Mathematics and Statistics at the University at Albany - SUNY, and a Postdoctoral Fellow at the Institute for Mathematics and its Applications at the University of Minnesota for the 2013-2014 thematic year on applications of topology.",https://events.umich.edu/event/118001,"Weiser Hall",747,"Weiser Hall",,Mathematics,"The Center for the Study of Complex Systems
The College of Literature, Science, and the Arts
Department of Physics
Department of Statistics"
117416-21839273,"2024-02-08 16:00:00","2024-02-08 17:30:00","Pro-representable formal moduli and examples","Alex Bauman","Workshop / Seminar",TBA,https://events.umich.edu/event/117416,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Learning Seminar - Department of Mathematics
Department of Mathematics"
118366-21840941,"2024-02-08 16:00:00","2024-02-08 16:50:00","Student Dyn/Geo/Top: Poisson Geometry and Symplectic Groupoids","Reebhu Bhattacharyya","Workshop / Seminar","In this talk, we will give a basic introduction to Poisson geometry and examine the relation between Poisson manifolds and symplectic groupoids. If time permits, we will examine how this relates to deformation quantization. Only a basic familiarity with manifolds will be assumed.",https://events.umich.edu/event/118366,"East Hall",2866,"East Hall",,Mathematics,"Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
116881-21838141,"2024-02-08 18:30:00","2024-02-08 19:00:00","Michigan in Washington Information Session",,Meeting,"Please join us to learn about the Michigan in Washington program and how it can help you achieve your career goals. https://umich.zoom.us/j/96067832605",https://events.umich.edu/event/116881,"Off Campus Location",https://umich.zoom.us/j/96067832605,Virtual,,Mathematics,"Michigan in Washington Program"
114765-21833580,"2024-02-09 15:00:00","2024-02-09 16:00:00","AIM Seminar/Smereka Prize Lecture: Mathematical Modeling of Circadian Rhythms from Wearable Data","Caleb Mayer, Stanford University","Lecture / Discussion","Abstract: Models that capture the human circadian clock on a macroscopic level have been used effectively in predicting circadian phase, particularly for day worker and healthy populations. Adapting and applying these models to work with wearable data from populations with disrupted circadian phases (such as shift workers, cancer patients, and individuals with COVID-19) has been a recent key area of research. This talk will present limit cycle oscillator models for the circadian pacemaker, show their ability to predict human circadian phase based on real-world activity data from consumer-grade wearable devices, and consider the effects of lighting schedules and parameters on the model outputs. We will further discuss algorithms for the analysis of oscillatory wearable data such as heart rate and body temperature, and the application of these techniques to varying populations. Through this framework we see changes to physiologically-relevant features at different times around COVID-19 symptom onset, enhancing our understanding of disease progression and speaking to the early detection potential. These projects aim to utilize mathematical and computational tools to generate meaningful additions to our understanding of circadian rhythms, personal health, and disease in the real-world.
Contact: S. Alben",https://events.umich.edu/event/114765,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
118359-21840935,"2024-02-09 15:00:00","2024-02-09 16:00:00","Compactifying the universal elliptic curve using toric geometry","Hyunsuk Kim","Workshop / Seminar","One can compactify the universal elliptic curve by the following strategy: the moduli is an open 1-dimensional variety, so you can uniquely compactify it. And then the universal elliptic curve is 2-dimensional, so you can compactify whatever you want and choose the minimal resolution. I'll try to convince you that this is bad and explain how you can do better in a systematic way.",https://events.umich.edu/event/118359,"East Hall",4088,"East Hall",,Mathematics,"Student Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
116409-21836745,"2024-02-09 15:00:00","2024-02-09 16:00:00","The combinatorics of minuscule posets in mirror symmetry for homogeneous spaces","Peter Spacek, TU Chemnitz","Workshop / Seminar","We will demonstrate the various ways minuscule posets appear in mirror symmetry statements for cominuscule homogeneous spaces in the joint work with Charles Wang (UMich). The mirror models of these spaces arise through Langlands duality, and hence use the corresponding minuscule representations. The weight spaces of these representations can be described using minuscule posets, so it is not surprising that the combinatorics of these posets govern the various objects appearing.",https://events.umich.edu/event/116409,"East Hall",4096,"East Hall",,Mathematics,"Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
115248-21834267,"2024-02-09 16:00:00","2024-02-09 17:00:00","GEOMETRY SEMINAR: Exponential Mixing Via Additive Combinatorics","OSAMA KHALIL","Workshop / Seminar","The Bowen-Ruelle conjecture predicts that geodesic flows on negatively curved manifolds are exponentially mixing with respect to all their equilibrium states. Dolgopyat pioneered a method rooted in the thermodynamic formalism that settled the conjecture for surfaces. Soon after, Liverani developed an intrinsic functional analytic analog of Dolgopyat's method allowing to settle the case of Liouville measures in higher dimensions, while simultaneously producing more information on the rates of mixing. Despite these important breakthroughs, the conjecture remains open in general, even in the case of measures of maximal entropy. In this talk, we will discuss a method for extending the functional analytic approach to deal with non-smooth invariant measures in a concrete algebraic setting. The key ingredient is a reduction of the problem to one regarding Fourier transforms of dynamically defined measures which we address using new machinery in additive combinatorics. The talk will not assume prior knowledge of these topics.",https://events.umich.edu/event/115248,"East Hall",3866,"East Hall",,Mathematics,"Department of Mathematics
Geometry Seminar - Department of Mathematics"
117733-21839927,"2024-02-12 12:00:00","2024-02-12 13:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117826-21840078,"2024-02-12 15:00:00","2024-02-12 16:00:00","RTG NT: Theta correspondence and Arthur packets","Alex Hazeltine","Workshop / Seminar","Abstract: The local theta correspondence does not preserve L-packets. As a remedy, Adams conjectured that instead of L-packets, the theta correspondence preserves Arthur packets. Moeglin verified Adams' conjecture when the theta correspondence has sufficiently large rank. Moeglin also showed that Adams' conjecture fails in low rank. Bakic and Hanzer showed that the failure can be managed: namely if Adams conjecture holds at some rank then it holds in any higher rank. In this talk, we discuss how to understand the failure of Adams' conjecture in low rank and how to remedy it.",https://events.umich.edu/event/117826,"East Hall",3088,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
118702-21841491,"2024-02-12 16:00:00","2024-02-12 17:00:00","Student Combinatorics: Long mutation cycles","Scott Neville","Workshop / Seminar","A cluster algebra is a ring defined by combinatorial data: a quiver viewed up to mutation equivalence. The mutation graph of a (mutation) equivalence class of quivers has a vertex for each quiver and an edge between two vertices if their quivers are related by a mutation. A mutation cycle is a cycle in this graph. We show that already for 4-vertex quivers there are examples of mutation cycles that have arbitrarily large length and cannot be paved by shorter cycles, and discuss other constructions of mutation cycles. This talk is based on joint work with Sergey Fomin.",https://events.umich.edu/event/118702,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
112526-21829080,"2024-02-12 16:15:00","2024-02-12 17:15:00","GLNT: Traces of random matrices over finite fields and cancellation in character sums","Valeriya Kovaleva (CRM/Université de Montréal)","Workshop / Seminar","Let X be a matrix drawn uniformly at random from GL_n(F_q), then one may conjecture that traces of powers of such matrices Tr(X^k) should have an asymptotically uniform distribution F_q. Further, one may wonder how robust this phenomenon is and how large can k be. On the one hand, this question is an analogue of a classic problem from random matrix theory, and, on the other hand, it is intimately related to short character sums over function fields with the power k serving as the conductor. In our work, we prove that the distribution of Tr(X^k) is indeed asymptotically uniform and that the respective short interval character sums exhibit cancellation for k = q^{o(n^2)}. This is a much wider range than one could hope to obtain for general characters, and in fact, this phenomenon seems to have no analogue over the integers. This is joint work with Ofir Gorodetsky.",https://events.umich.edu/event/112526,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
117940-21840213,"2024-02-13 16:00:00","2024-02-13 17:00:00","Math Undergraduate Seminar: Parallel Algebraic Multigrid Methods for Higher-Order PDEs","Kellen Kanarios","Lecture / Discussion","Existing algebraic multigrid (AMG) methods rely on assumptions about the near-kernel components of a given linear system. Namely, that these components are ""smooth"" in the sense that they can be sufficiently approximated by few degrees of freedom. PDEs with higher order terms violate these assumptions, causing an unbounded number of $V$-cycles for convergence. As an example, we introduce a PDE that arises in kinetic-edge plasma simulation. This PDE contains an isotropic fourth-order term, making existing methods infeasible. In this work, we propose an $O(n)$ highly-parallelizable exact method to solve the system solely containing the isotropic fourth-order term. We then extend this algorithm to solve the original system, including periodic boundary conditions. Our algorithm obtains drastic improvement over existing methods.",https://events.umich.edu/event/117940,"East Hall",B743,"East Hall",,Mathematics,"Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
118237-21840683,"2024-02-13 16:00:00","2024-02-13 17:00:00","Point counting over finite fields and the cohomology of moduli spaces of curves","Sam Payne (UT Austin)","Workshop / Seminar","Algebraic geometry studies solution sets of polynomial equations. For instance, over the complex numbers, one may examine the topology of the solution set, whereas over a finite field, one may count its points. For polynomials with integer coefficients, these two fundamental invariants are intimately related via cohomological comparison theorems and trace formulas for the action of Frobenius. I will discuss the general framework relating point counting over finite fields to topology of complex algebraic varieties and also present recent applications to the cohomology of moduli spaces of curves that resolve longstanding questions in algebraic geometry and confirm more recent predictions from the Langlands program.",https://events.umich.edu/event/118237,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
118372-21840949,"2024-02-13 18:00:00","2024-02-13 19:30:00","Trading at Optiver: Tech Talk and Info Session",,"Careers / Jobs","Are you intrigued by the dynamic world of trading and finance? Join us for an evening event hosted by Optiver in collaboration with MIG and MFAMS, where the topic of trading takes center stage. Whether you're a future trader, aspiring equity analyst, or simply fascinated by the financial markets, this event is made for you. There will be 12 Joe's pizzas for attendees.
Be sure to register using the link attached.",https://events.umich.edu/event/118372,"Central Campus Classroom Building",0420,"Central Campus Classroom Building",,Mathematics,"Michigan Finance and Mathematics Society"
117733-21839899,"2024-02-14 10:00:00","2024-02-14 23:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117206-21838823,"2024-02-14 11:00:00","2024-02-14 12:00:00","Computing stable representations of graph configuration spaces","Claudia Yun (Michigan)",Presentation,"An n-pointed configuration space of a topological space X parametrizes n distinct points in X. Configuration spaces of higher dimensional manifolds have been studied widely, but less is known when X is a graph. We consider a family of graphs $G_n$ with compatible $S_n$-actions. Fixing the number of points k, the homology groups of the k-configuration spaces of these graphs exhibit representation stability for many families. Examples include the star graphs, complete graphs, and the Kneser graphs. Our goal is to explicitly compute these stable representations. We use a discretized model for the configuration spaces developed by Abrams that has a cellular decomposition in terms of the combinatorics of the graphs and we perform our computations in the software system SageMath. We will present some partial results in the cases k=2 and G is a star graph and a complete graph. This is joint work with Eric Ramos.
Note regarding location: The Pillsbury room is located on Floor 4M on the Psychology side of East Hall. To get to the room, you enter the Psychology side of East Hall from the Church Street entrance and before you get into the Psych atrium, there is an elevator to your left. Take the elevator to Floor 4M and the elevator opens into the room.",https://events.umich.edu/event/117206,"East Hall","Pillsbury Room","East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
118713-21841502,"2024-02-14 14:30:00","2024-02-14 16:00:00","Learning Seminar in Algebraic Combinatorics: Properness and projectivity of toric varieties","Hyunsuk Kim","Workshop / Seminar","Continuing from last week, we will continue discussing properness and projectivity of toric varieties. Along the way, we will study the divisors and line bundles on toric varieties with some explicit examples.",https://events.umich.edu/event/118713,"East Hall",4088,"East Hall",,Mathematics,"Learning Seminar in Algebraic Combinatorics - Department of Mathematics
Department of Mathematics"
118660-21841377,"2024-02-14 15:00:00","2024-02-14 16:00:00","Student CA Seminar - Social Hour",,"Workshop / Seminar","Join us for a social hour with snacks, board games, and math-themed Valentine's Day cards!
(Image credit: Anna Brosowsky)",https://events.umich.edu/event/118660,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
118697-21841415,"2024-02-14 15:00:00","2024-02-14 15:50:00","Student Number Theory: Period integrals of automorphic forms and distinction problems","Guanjie Huang","Workshop / Seminar","In this talk we are going to introduce the theory of period integrals. In particular, we are going to see many interplays between local and global distinction problems.",https://events.umich.edu/event/118697,"East Hall",5822,"East Hall",,Mathematics,"Student Number Theory Seminar - Department of Mathematics
Department of Mathematics"
115340-21834474,"2024-02-14 16:00:00","2024-02-14 17:30:00","Algebraic Geometry Seminar: Towards a geometric version of the monodromy conjecture","Ming Hao Quek (Stanford)","Workshop / Seminar","The monodromy conjecture of Denef—Loeser predicts that given a complex polynomial f, and any pole s of its motivic zeta function, exp(2πis) is a ""monodromy eigenvalue"" associated to f. In this talk I will formulate a geometric version of the conjecture and elaborate on ongoing work, starting from the case of Newton non-degenerate hypersurfaces. These are hypersurface singularities whose singularities are governed, up to a certain extent, by faces of their Newton polyhedra. The extent to which the former is governed by the latter is a key aspect of the conjecture. If time permits, I will also sketch a recent pursuit to reduce the conjecture to a setting that is slightly more general than the case of Newton non-degenerate hypersurfaces.",https://events.umich.edu/event/115340,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
118721-21841526,"2024-02-14 16:00:00","2024-02-14 17:30:00","Logic Seminar: Functorial Semantics of Horn theories, continued","Johnson He","Workshop / Seminar","We continue from last week by describing a hyperdoctrine for equational theories. Then with an eye towards full first-order logic, we discuss the Frobenius and Beck-Chevalley conditions.",https://events.umich.edu/event/118721,"East Hall",5822,"East Hall",,Mathematics,"Logic Seminar - Department of Mathematics
Department of Mathematics"
118755-21841567,"2024-02-15 16:00:00","2024-02-15 17:00:00","Versal deformations and algebraization","Shend Zhjeqi","Workshop / Seminar",TBA,https://events.umich.edu/event/118755,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Learning Seminar - Department of Mathematics
Department of Mathematics"
114764-21833579,"2024-02-16 15:00:00","2024-02-16 16:00:00","AIM Seminar: Inverse wave scattering via data driven reduced order modeling","Liliana Borcea, University of Michigan","Lecture / Discussion","Abstract: This talk is concerned with the following inverse problem for the wave equation: Determine the variable wave speed from data gathered by a collection of sensors, which emit probing signals and measure the generated backscattered waves. Inverse backscattering is an interdisciplinary field driven by applications in geophysical exploration, radar imaging, non-destructive evaluation of materials, etc. There are two types of methods:
(1) Qualitative (imaging) methods, which address the simpler problem of locating reflective
structures in a known host medium.
(2) Quantitative methods, also known as velocity estimation. Typically, velocity estimation is
formulated as a PDE constrained optimization, where the data are fit in the least squares sense by
the wave computed at the search wave speed. The increase in computing power has lead to growing interest in this approach, but there is a fundamental impediment, which manifests especially for high frequency data: The objective function is not convex and has numerous local minima even in the absence of noise. The main goal of the talk is to introduce a novel approach to
velocity estimation, based on a reduced order model (ROM) of the wave operator. The ROM is called
data driven because it is obtained from the measurements made at the sensors. The mapping between these measurements and the ROM is nonlinear, and yet the ROM can be computed efficiently using methods from numerical linear algebra. More importantly, the ROM can be used to define a better objective function for velocity estimation, so that gradient based optimization can succeed even for a poor initial guess.
(Joint work with Josselin Garnier, Alexander Mamonov and John Zimmerling)
Contact: AIM Seminar Organizers",https://events.umich.edu/event/114764,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
118708-21841497,"2024-02-16 15:00:00","2024-02-16 16:00:00","Semiabelian degeneration of abelian varieties","Alex Bauman","Workshop / Seminar","A semiabelian scheme over a variety X is a smooth group variety G over X whose fibers are extensions of an abelian variety by a torus. I will discuss the ways that abelian varieties can degenerate into semiabelian varieties, following Faltings and Chai, and maybe some applications to compactifications of the moduli of abelian varieties.",https://events.umich.edu/event/118708,"East Hall",4088,"East Hall",,Mathematics,"Student Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
117444-21839319,"2024-02-16 15:00:00","2024-02-16 16:00:00","Tensor categories for Sets and Trees","Ilia Nekrasov, University of Michigan","Workshop / Seminar","Recently, Andrew Snowden and Nate Harman introduced a new technique for constructing tensor categories using some model-theoretic gadgets. The key ingredients are a group and a tensorial measure on this group. Interesting examples come from automorphism groups of ""big"" combinatorial objects. Noticeably, the corresponding measures can be defined and computed via combinatorics of finite counterparts of these ""big"" objects.
In this talk, I will give a friendly introduction to the topic and then focus on examples:
Deligne’s categories Rep(S_t) corresponding to plain sets and arboreal categories Rep(T_t) corresponding to trees.",https://events.umich.edu/event/117444,"East Hall",4096,"East Hall",,Mathematics,"Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
118720-21841525,"2024-02-16 16:00:00","2024-02-16 17:00:00","GEOMETRY SEMINAR : Intro to higher-rank measure rigidity and the Einsieder-Lindenstrauss theorem","Asaf Katz","Workshop / Seminar","I will try to explain the fundamental strategy of Katok-Spatzier for higher-rank measure rigidity, highlighting the crucial role played by leafwise measures.
Then we will state the recent measure rigidity theorem of Einsiedler-Lindenstrauss and try to provide an overview of the proof, indicating the steps and the constructions which will be presented later in the seminar. The talk should be (essentially) accessible and independent from the previous talk by Ralf.",https://events.umich.edu/event/118720,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics"
118316-21840878,"2024-02-16 16:00:00","2024-02-16 17:30:00","Preprint Algebraic Geometry Seminar: Bernstein-Sato theory modulo p^m, after Bitoun and Quinlan-Gallego","Jonghyun Lee (UM)","Workshop / Seminar",TBA,https://events.umich.edu/event/118316,"East Hall",4096,"East Hall",,Mathematics,"Preprint Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
116410-21836759,"2024-02-17 10:30:00","2024-02-17 11:30:00","Saturday Morning Physics | Totally Awesome: Your Guide to the Great American Solar Eclipse of 2024","David Gerdes, Arthur F. Thurnau Professor of Physics, Chair of Physics Department (U-M)",Presentation,"Join us in person or via live stream: https://youtu.be/ZjFTC5tdtLw
A total solar eclipse is one of the most unforgettable and awe-inspiring natural events we can experience. On April 8, 2024, people in southeast Michigan will have our last opportunity for decades to witness a total eclipse less than a few hours' drive away. I'll describe the science behind eclipses, the role they have played in history, and how and where to best experience this year's eclipse.",https://events.umich.edu/event/116410,"Weiser Hall","170 & 182","Weiser Hall",,Mathematics,"Saturday Morning Physics
Department of Astronomy
Department of Physics
LSA AEM
Applied Physics
LSA Biophysics
Undergrad Physics Events"
117733-21839928,"2024-02-19 12:00:00","2024-02-19 13:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117827-21840079,"2024-02-19 15:00:00","2024-02-19 16:00:00","RTG NT: Polynomial factorization modulo many primes","Dan Altman","Workshop / Seminar","Abstract: The fastest known deterministic algorithms for factorising polynomials in F_p[x] have a worst-case runtime that is exponential in log p. We will discuss a new deterministic algorithm which factorises an integer polynomial modulo many primes simultaneously with amortised runtime that is polynomial in log p. Based on joint work with David Harvey.",https://events.umich.edu/event/117827,"East Hall",3088,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
117622-21839714,"2024-02-19 16:00:00","2024-02-19 17:00:00","ISRMT seminar: Ablowitz-Ladik lattice and the Circular β-ensemble: a (kind of) surprising connection","Guido Mazzuca (Tulane University)","Workshop / Seminar","In this talk, we focus on the interplay between the theory of integrable systems, and random matrix theory.
This connection was first realized by H. Spohn, who was able to compute the density of states for the Toda lattice by connecting it to the corresponding one of the Gaussian β ensemble, a well known random matrix model. The computation of this quantity enabled him to apply the theory of generalized hydrodynamics, so to compute the correlation functions for the Toda lattice.
In this talk, I consider another integrable model, namely the Ablowitz-Ladik lattice; I introduce the Generalized Gibbs ensemble for this lattice, and I relate it with the so-called Circular β ensemble, a classical random matrix model for unitary matrices. This allows us to compute explicitly the density of states for the Ablowitz-Ladik lattice in terms of the one of this random matrix ensemble.
This talk is mainly based on these two papers:
G. M. , and T. Grava: Generalized Gibbs ensemble of the Ablowitz-Ladik lattice, circular β- ensemble and double confluent Heun equation. Communication in Mathematical Physics. DOI: 10.1007/s00220-023-04642-8
G. M., and R. Memin: Large Deviations for Ablowitz-Ladik lattice, and the Schur flow. Electronic Journal of Probability. DOI: 10.1214/23-EJP941",https://events.umich.edu/event/117622,"East Hall",EH1866,"East Hall",,Mathematics,"Integrable Systems and Random Matrix Theory Seminar - Department of Mathematics
Department of Mathematics"
119011-21842030,"2024-02-19 16:00:00","2024-02-19 17:00:00","Quantitative Transversal Theorems in the Plane","João Pedro Carvalho",Meeting,"Helly's theorem is a foundational result in geometric combinatorics providing a condition for the non-emptiness of the intersection of a collection of convex sets in Euclidean space. Hadwiger's theorem is a variant of Helly-type theorems involving common transversals to families of convex sets instead of common intersections. In this talk, we discuss these theorems, as well as a quantitative and colorful version of Hadwiger's theorem on the plane.",https://events.umich.edu/event/119011,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
115812-21835662,"2024-02-19 16:00:00","2024-02-19 17:00:00","Ziwet Lecture I | Morrey's theory and direct methods of the calculus of variations","Wilfrid Gangbo (UCLA)","Lecture / Discussion","In the middle of the last century, Charles Morrey introduced the notions of poly-convexity, rank-one-convexity and quasi-convexity functions, to study variational problems. While the first two notions are local conditions, the third one which turned out to be the most important one, is a non local and poorly understood notion. In this talk we comment on Morrey's conjecture and Iwaniec's conjecture on the Beurling-Ahlfors Transform.",https://events.umich.edu/event/115812,"East Hall",1360,"East Hall",,Mathematics,"Special Events - Department of Mathematics
Computer Science and Engineering Division
Department of Mathematics"
112527-21829081,"2024-02-19 16:15:00","2024-02-19 17:15:00","GLNT: Random multiplicative functions: old and new results","Max Wenqiang Xu (Stanford)","Workshop / Seminar","Random multiplicative functions are probabilistic models for important arithmetic functions in number theory, e.g. Mobius function, Dirichlet characters. In this talk, I would like to introduce the topic and emphasize some recent developments. Part of the talk is based on joint works with Angelo, Harper, and Soundararajan.",https://events.umich.edu/event/112527,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
119009-21842027,"2024-02-20 15:00:00","2024-02-20 16:00:00","Student AIM Seminar: Microhydrodynamics of a confined autophoretic particle","Günther Turk","Workshop / Seminar","Abstract: Artificial micro-swimmers are vital in the study of biological systems and non-equilibrium phenomena. A prime example is given by autophoretic particles, such as Janus particles, which self-propel due to asymmetric chemical interactions on their surface. The chemical gradients generated by the particle induce an osmotic pressure, which is balanced by viscous stresses driving an effective slip flow confined to a thin layer at the surface of the particle. The particle thus sets the surrounding fluid in motion, which then reacts back on the particle, creating surface stresses and eventually self-propulsion. Here, we develop an analytical and numerics-friendly formalism to study autophoresis based on general principles such as linearity of the governing equations. Choosing a kinetic approach, thermal fluctuations of the suspending fluid are included systematically. After discussing the central ideas of our method, we study the concrete example of a bottom-heavy Brownian Janus particle in confinement. Finally, we give an outlook on potential future applications.",https://events.umich.edu/event/119009,"Off Campus Location",,https://umich.zoom.us/j/97799225009,,Mathematics,"Student AIM Seminar - Department of Mathematics
Department of Mathematics"
119030-21842049,"2024-02-20 16:00:00","2024-02-20 17:00:00","Math Undergraduate Seminar: In-Duck-Tion","Martha Wolf","Lecture / Discussion","Show up and find out!",https://events.umich.edu/event/119030,"East Hall",B743,"East Hall",,Mathematics,"Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
107836-21817093,"2024-02-20 16:00:00","2024-02-20 17:00:00","Ziwet Lecture II | On differentiability in the Wasserstein space","Wilfrid Gangbo (UCLA)","Workshop / Seminar","We consider P₂(Rᵈ), the set of Borel probability measures of finite second moments on Rᵈ, which we endow with the Wasserstein metric W₂. It is well–known that P₂(Rᵈ), W₂), is isometric to a quotient space of the Hilbert space H of square-integrable random variables on (0, 1)ᵈ. We elucidate the connection between various notions of differentiability in the Wasserstein space: some have been introduced intrinsically (in the Wasserstein space, by using typical objects from the theory of Optimal Transport). Another notion is extrinsic and arises from the identification of the Wasserstein space with the Hilbert space of square-integrable random variables on a non-atomic probability space.",https://events.umich.edu/event/107836,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Computer Science and Engineering Division
Department of Mathematics
Special Events - Department of Mathematics"
119153-21842270,"2024-02-20 20:00:00","2024-02-20 21:00:00","MATH LCIT CONVERSATION",,"Lecture / Discussion","In this meeting, we will continue our discussion of Reinholtz's book, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester, we started discussion of the text, discussing the material through the beginning of chapter 3 (roughly, sections 1.1, 2.3.5-2.4, and 3.1-3.2). For this meeting, we will discuss sections 3.3 through the end of chapter 4. Meetings of the LCIT occur in East Hall room 4866.",https://events.umich.edu/event/119153,"East Hall","EH 4866","East Hall",,Mathematics,"Learning Community on Inclusive Teaching in Mathematics - Department of Mathematics
Department of Mathematics"
119153-21842271,"2024-02-20 20:00:00","2024-02-20 21:00:00","MATH LCIT CONVERSATION",,"Lecture / Discussion","In this meeting, we will continue our discussion of Reinholtz's book, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester, we started discussion of the text, discussing the material through the beginning of chapter 3 (roughly, sections 1.1, 2.3.5-2.4, and 3.1-3.2). For this meeting, we will discuss sections 3.3 through the end of chapter 4. Meetings of the LCIT occur in East Hall room 4866.",https://events.umich.edu/event/119153,"East Hall",,"East Hall",,Mathematics,"Learning Community on Inclusive Teaching in Mathematics - Department of Mathematics
Department of Mathematics"
119153-21842272,"2024-02-20 20:00:00","2024-02-20 21:00:00","MATH LCIT CONVERSATION",,"Lecture / Discussion","In this meeting, we will continue our discussion of Reinholtz's book, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester, we started discussion of the text, discussing the material through the beginning of chapter 3 (roughly, sections 1.1, 2.3.5-2.4, and 3.1-3.2). For this meeting, we will discuss sections 3.3 through the end of chapter 4. Meetings of the LCIT occur in East Hall room 4866.",https://events.umich.edu/event/119153,,,,,Mathematics,"Learning Community on Inclusive Teaching in Mathematics - Department of Mathematics
Department of Mathematics"
117733-21839900,"2024-02-21 10:00:00","2024-02-21 23:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117200-21838817,"2024-02-21 11:00:00","2024-02-21 12:00:00","Stability and Periodicity Phenomena for Cohomology of Sheaves","Keller VandeBogert (Notre Dame)",Presentation,"The problem of computing the cohomology of line bundles on flag varieties in arbitrary characteristic has remained an open question despite decades of study and many important results. A more recent perspective on this problem has instead focused on stability; more precisely, how does the cohomology of a fixed line bundle vary as the dimension of the ambient flag becomes arbitrarily large? In recent joint work with Raicu, we answer this: the cohomology is eventually modeled by a fixed polynomial functor, depending only on the weight of the line bundle. Moreover, for certain classes of weights, we can show that these stability functors exhibit remarkable periodicity properties determined by the characteristic of the underlying field. In this talk, we will see some of the background and tools that go into these results, including an unexpected connection to a long-open problem of Akin--Buchsbaum on ""universal"" categorifications of the Jacobi-Trudi identity.",https://events.umich.edu/event/117200,"East Hall","Pillsbury Room","East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
118499-21841151,"2024-02-21 12:00:00","2024-02-21 13:00:00","MPSDS JPSM Seminar Series - Recent Developments and Open Problems in Post-Linkage Data Analysis","Martin P. Slawski - George Mason University.","Lecture / Discussion","MPSDS JPSM Seminar Series
February 7, 2024
12:00 - 1:00
In person, room 1070 Institute for Social Research, and via Zoom.
The Zoom call will be locked 10 minutes after the start of the presentation.
Recent Developments and Open Problems in Post-Linkage Data Analysis
Record linkage and subsequent data analysis of the linked file with suitable propagation of uncertainty can be performed if the analyst also happens to be the linker or at least has comprehensive information about how the data were linked. However, it is rather common that the two processes are considered in a separate fashion, with the analyst being handed a linked file that is possibly subject to substantial linkage error (false matches and missed matches). Ignoring such error can render statistical analysis invalid. At the same time, accounting for linkage error with limited information about the linkage process poses a variety of challenges. This talk will outline a framework based on a mixture model for addressing mismatch error in the secondary analysis of linked files. Its use will be demonstrated in several case studies. Finally, we will present recent extensions, future directions and open problems.
Martin Slawski is an Associate Professor in the Department of Statistics at George
Mason University. His research on data analysis after record linkage is currently
supported by NSF. His research interests concern topics in computational statistics and applications in various domains. He serves as an associate editor of the Electronic Journal of Statistics. He received his Ph.D. in Computer Science from Saarland University, Germany, and was a postdoctoral associate in Statistics and Computer
Science at Rutgers University prior to joining his current institution.",https://events.umich.edu/event/118499,"Institute For Social Research","Room 1070, Institute for Social Research","Institute For Social Research",,Mathematics,"Michigan Program in Survey and Data Science
Institute for Social Research
Survey Research Center"
119013-21842033,"2024-02-21 14:30:00","2024-02-21 16:00:00","Learning Seminar in Algebraic Combinatorics: Introduction to Symplectic Toric Manifolds and the Moment Map","Paul Mammen","Workshop / Seminar","In this talk I will will be looking at toric geometry from a symplectic point of view. We will begin by looking at symplectic manifolds. There are natural actions of Lie groups on such manifolds and we will define certain maps called moment maps. In the case of torus actions, we will discuss results by Atiyah-Guillemin-Sternberg and Delzant, relating convex polytopes and toric manifolds, via moment maps.",https://events.umich.edu/event/119013,"East Hall",4088,"East Hall",,Mathematics,"Learning Seminar in Algebraic Combinatorics - Department of Mathematics
Department of Mathematics"
118997-21842012,"2024-02-21 15:00:00","2024-02-21 15:50:00","Student Number Theory: ABC Conjecture in Function Fields","Ming Yean Lim","Workshop / Seminar","The rings Z and F_q[T] share many properties in common, so one might try to study number theory over F_q[T]. A (global) function field is a finite extension of F_q(T), just as a number field is a finite extension of Q. In this talk I will discuss the function field analogy. In particular, we will sketch a proof of an analogue of the ABC conjecture and Fermat’s last theorem in function fields.",https://events.umich.edu/event/118997,"East Hall",5822,"East Hall",,Mathematics,"Student Number Theory Seminar - Department of Mathematics
Department of Mathematics"
118704-21841493,"2024-02-21 16:00:00","2024-02-21 17:30:00","Algebraic Geometry Seminar: Generic character sheaves on parahoric subgroups","Charlotte Chan (UM)","Workshop / Seminar","Lusztig's theory of character sheaves for connected reductive groups is one of the most important developments in representation theory in the last few decades. In this talk, I will describe some basic algebro-geometric techniques underlying this theory and explain the need for a theory of character sheaves on jet schemes of reductive groups from the perspective of the Langlands program. Recently, R. Bezrukavnikov and I have developed the ""generic"" part of this desired theory. In the simplest nontrivial case, this resolves a conjecture of Lusztig and produces perverse sheaves on jet schemes compatible with parahoric Deligne--Lusztig induction.",https://events.umich.edu/event/118704,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
117908-21840179,"2024-02-21 16:00:00","2024-02-21 18:00:00","AmplifyME x MFAMS: Finance Accelerator Simulation",,"Careers / Jobs","Join us on Wednesday, February 21st from 4-6 PM in B2560 for a financial trading simulation. This is for students interested in gaining real-world experience in roles such as Investment Banking and Asset Management. The 2-hour event can fast-track students through to our Morgan Stanley interviews and is available both in person or virtually. Register through the web link attached!",https://events.umich.edu/event/117908,"Jeff T. Blau Hall",B2560,"Jeff T. Blau Hall",,Mathematics,"Michigan Finance and Mathematics Society"
118235-21840682,"2024-02-21 16:00:00","2024-02-21 17:20:00","RTG GeomDynTop Seminar: Fibrations by pencils of quadrics and maximal representations","Colin Davalo","Workshop / Seminar","The hyperbolic 3-manifold associated to a Fuchsian
representation of a surface group admits a fibration over the surface with geodesic fibers that extends to a fibration of the conformal boundary. This also holds for almost Fuchsian representations, but not in general for quasi-Fuchsian representations.
I will present an analog of this picture for representations of surface groups into Sp(2n,R). Among these representations, there exists a union of connected components containing only discrete and faithful representations, called maximal representations. We will consider fibrations by projective codimension $2$ subspaces of a projective convex set containing the symmetric space of Sp(2n,R). These subspaces are described by pencils of quadrics, and we will see that one can characterize maximal representations by the existence of such a continuous fibration, satisfying some additional properties. The hyperbolic 3-manifold associated to a Fuchsian representation of a surface group admits a fibration over the surface with geodesic fibers that extends to a fibration of the conformal boundary. This also holds for almost Fuchsian representations, but not in general for quasi-Fuchsian representations.",https://events.umich.edu/event/118235,"East Hall",3866,"East Hall",,Mathematics,"RTG Seminar on Geometry, Dynamics and Topology - Department of Mathematics
Department of Mathematics"
115813-21835663,"2024-02-21 16:00:00","2024-02-21 17:00:00","Ziwet Lecture III | Hamilton-Jacobi equations in the Wasserstein space","Wilfrid Gangbo (UCLA)","Lecture / Discussion","We show that the classical theory of well-posedness for viscosity solutions for Hamilton-Jacobi equations in infinite-dimensional Hilbert spaces is brought to bear on well-posedness for Hamilton-Jacobi equations in the Wasserstein space.",https://events.umich.edu/event/115813,"East Hall",1360,"East Hall",,Mathematics,"Special Events - Department of Mathematics
Computer Science and Engineering Division
Department of Mathematics"
110937-21825884,"2024-02-21 17:00:00","2024-02-21 18:00:00","On Perturbations of Preferences and Indifference Price Invariance","Oleksii Mostovyi","Workshop / Seminar","We investigate indifference pricing under perturbations of preferences in small and large markets. We establish stability results for small perturbations of preferences, where the latter can be stochastic. We obtain a sharp condition in terms of the associated concave and convex envelopes and provide counterexamples demonstrating that, in general, stability fails. Next, we investigate a class of models where the indifference price does not depend on the preferences or the initial wealth. Here, under the existence of an equivalent separating measure, in the settings of deterministic preferences, we show that the class of indifference price invariant models is the class of models where the dual domain is stochastically dominant of the second order. We also provide a counterexample showing that, in general, this result does not hold over stochastic preferences, where instead, we show that the indifference price invariant models are complete models (in both small and large markets). In the process, we establish a theorem of independent interest on the stability of the optimal investment problem under perturbations of preferences. Our results are new in both small and large markets, and thus, in particular, we introduce large stochastically dominant models, give examples of such models, and characterize them as the indifference price invariant ones over deterministic preferences.",https://events.umich.edu/event/110937,"East Hall",1360,"East Hall",,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
117417-21839276,"2024-02-22 16:00:00","2024-02-22 17:30:00","Artin's axioms 1","Kenneth Ma","Workshop / Seminar",TBA,https://events.umich.edu/event/117417,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Learning Seminar - Department of Mathematics
Department of Mathematics"
117313-21839159,"2024-02-22 16:00:00","2024-02-22 17:00:00","Commutative Algebra Seminar: The Total Rank Conjecture in Characteristic Two","Keller VandeBogert (Notre Dame)","Workshop / Seminar","The total rank conjecture is a coarser version of the Buchsbaum-Eisenbud-Horrocks conjecture which, loosely stated, predicts that modules with large annihilators must also have ""large"" syzygies. In 2017, Walker proved that the total rank conjecture holds over rings of odd characteristic, using techniques that heavily relied on the invertibility of 2. In this talk, I will speak on joint work with Walker where we settle (and generalize) the total rank conjecture over k-algebras of arbitrary characteristic. Our techniques take advantage of the classical Dold-Kan correspondence and allow us to prove an even stronger version of the total rank conjecture when the field k has characteristic 2.",https://events.umich.edu/event/117313,"East Hall",3088,"East Hall",,Mathematics,"Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
119020-21842041,"2024-02-22 16:00:00","2024-02-22 16:50:00","Student Dyn/Geo/Top: The Nerve Lemma & Spectral Sequences","Urshita Pal","Workshop / Seminar","The Nerve Lemma is a useful tool that, under some hypotheses, lets one compute the homology of a space in terms of a simplicial complex built from an open cover of the space. In this talk we shall see the statement of this lemma, a proof glimpse by analyzing a certain double complex, and if time permits, a proof sketch via (a gentle introduction to) spectral sequences.",https://events.umich.edu/event/119020,"East Hall",2866,"East Hall",,Mathematics,"Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
114766-21833581,"2024-02-23 15:00:00","2024-02-23 16:00:00","AIM Seminar: Integral Equation Calculations for Electrostatics of Solvated Biomolecules","Robert Krasny, University of Michigan","Lecture / Discussion","Abstract: I will present a new version of the treecode-accelerated boundary integral Poisson-Boltzmann solver which computes the electrostatic potential on the molecular surface of a solvated biomolecule using a well-conditioned integral equation formulation. The new version utilizes the NanoShaper surface triangulation code, node-patch boundary integral discretization, a block preconditioner, and a GPU-accelerated fast multipole method based on barycentric Lagrange interpolation and dual tree traversal. Numerical results for protein 1A63 and two viral capsids (Zika, H1N1) demonstrate the code’s accuracy and efficiency. I will also discuss an extension of this approach to the Poisson-Nernst-Planck model for ion transport through channel proteins in cell membranes. This talk reports on joint work with Zhen Chao (Western Washington University), Weihua Geng (Southern Methodist University), Svetlana Tlupova (Farmingdale State College), Nathan Vaughn (LANL), Lei Wang (U-Wisconsin, Milwaukee), and Leighton Wilson (Cerebras Systems).
Contact: AIM Seminar Organizers",https://events.umich.edu/event/114766,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
119003-21842021,"2024-02-23 16:00:00","2024-02-23 17:00:00","GEOMETRY SEMINAR: Intro to higher-rank measure rigidity and the Einsiedler-Lindenstrauss theorem","ASAF KATZ","Workshop / Seminar","We will state the recent measure rigidity theorem of Einsiedler-Lindenstrauss and try to provide an overview of the proof, indicating the steps and the constructions which will be presented later in the seminar. The talk should be (essentially) accessible and independent from the previous talks.",https://events.umich.edu/event/119003,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics"
118377-21840987,"2024-02-23 16:00:00","2024-02-23 17:30:00","Preprint Algebraic Geometry Seminar: the Bakker-Schnell proof of Hwang's theorem on base manifolds of Lagrangian fibrations,","Hyunsuk Kim (UM)","Workshop / Seminar",TBA,https://events.umich.edu/event/118377,"East Hall",4096,"East Hall",,Mathematics,"Preprint Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
117733-21839929,"2024-02-26 12:00:00","2024-02-26 13:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117733-21839901,"2024-02-28 10:00:00","2024-02-28 23:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
118350-21840926,"2024-02-28 16:00:00","2024-02-28 17:30:00","Special Algebraic Geometry Seminar: Refined transversality and equivariant positivity","Dave Anderson (Ohio State)","Workshop / Seminar","The standard Kleiman-Bertini transversality theorems say that if a variety is homogeneous with respect to the action of an algebraic group, then this action moves any two subvarieties into transverse position. I will describe refinements which treat cases where the action is not transitive, along with an application to the positivity of cohomology and K-theory classes of subvarieties of a generalized flag variety.",https://events.umich.edu/event/118350,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
118746-21841554,"2024-03-04 11:00:00","2024-03-04 12:00:00","ISRMT seminar: On the exact Gevrey order of formal Puiseux series solutions to the third Painlevé equation","Anastasia Parusnikova (HSE University)","Workshop / Seminar","I would like to speak about one rather old joint work with Andrey Vasilyev.
We consider the third Painlevé equation.
The Puiseux series formally satisfying it, asymptotically approximate of Gevrey order one solutions to this equation in sectors with the vertices at infinity.
A condition sufficient for the convergence of formal solutions of an ODE with analytic left-hand side is well-known.
On the other hand sufficient conditions for the divergence given in the same terms are unknown.
We present the family of values of the parameters such that these series are of exact Gevrey order one, and hence diverge. We prove the 1-summability of them and provide analytic functions which are approximated of Gevrey order one by these series in sectors with the vertices at infinity.",https://events.umich.edu/event/118746,"Off Campus Location",,Virtual,,Mathematics,"Integrable Systems and Random Matrix Theory Seminar - Department of Mathematics
Department of Mathematics"
117733-21839930,"2024-03-04 12:00:00","2024-03-04 13:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117828-21840080,"2024-03-04 15:00:00","2024-03-04 16:00:00","RTG NT: Modular degrees of elliptic curves over function fields","Lukas Scheiwiller","Workshop / Seminar","Abstract: The degree of the modular parametrization of an elliptic curve is an important invariant that is related to congruences of modular forms. In the case of an elliptic curve E over Q, the degrees of parameterizations of E by different Shimura curves are related to each other through Tamagawa numbers. We will discuss the analogous situation for elliptic curves over function fields, which admit different parameterizations by moduli of Drinfeld-Stuhler-modules.",https://events.umich.edu/event/117828,"East Hall",3088,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
119596-21843051,"2024-03-04 16:00:00","2024-03-04 17:00:00","Student Combinatorics: Introduction to Combinatorial Hopf Algebras","Dawei Shen","Workshop / Seminar","A combinatorial Hopf algebra is a graded connected Hopf algebra with finite-dimensional pieces equipped with a character. We will show that the quasi-symmetric (symmetric) functions can be made into a (cocommutative) combinatorial Hopf algebra and that it is the terminal object in the category of (cocommutative) combinatorial Hopf algebras. We will give examples of combinatorial Hopf algebras naturally arising from combinatorics and an application of this result to the study of affine Stanley symmetric functions.",https://events.umich.edu/event/119596,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
112529-21829083,"2024-03-04 16:15:00","2024-03-04 17:30:00",GLNT,TBA,"Workshop / Seminar",TBA,https://events.umich.edu/event/112529,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
119153-21842269,"2024-03-05 11:00:00","2024-03-05 12:30:00","MATH LCIT CONVERSATION",,"Lecture / Discussion","In this meeting, we will continue our discussion of Reinholtz's book, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester, we started discussion of the text, discussing the material through the beginning of chapter 3 (roughly, sections 1.1, 2.3.5-2.4, and 3.1-3.2). For this meeting, we will discuss sections 3.3 through the end of chapter 4. Meetings of the LCIT occur in East Hall room 4866.",https://events.umich.edu/event/119153,"East Hall",4866,"East Hall",,Mathematics,"Learning Community on Inclusive Teaching in Mathematics - Department of Mathematics
Department of Mathematics"
119697-21843420,"2024-03-05 16:00:00","2024-03-05 17:00:00","Math Undergraduate Seminar: Group Algebras","Abby Hess","Lecture / Discussion","How can we turn any group into an algebra? It’s simpler than you think. These objects also have some interesting applications and ties to representation theory and other algebraic areas of study.",https://events.umich.edu/event/119697,"East Hall",B743,"East Hall",,Mathematics,"Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
119406-21842687,"2024-03-05 17:00:00","2024-03-05 18:00:00","Student Analysis Seminar: General Relativity and the Einstein Equations","Chris Stith","Workshop / Seminar","From a mathematical viewpoint, general relativity (GR) lies at the intersection of differential geometry and partial differential equations. It is the study of manifolds whose curvature obeys certain properties (dictated by the Einstein equations), and also of various quantities of interest on these manifolds. These quantities usually have physically significant interpretations, and it is interesting to study how these quantities are affected by the underlying spacetime curvature. Since GR is a nonlinear theory, the quantities themselves also influence the underlying curvature. This talk will be an introduction to the mathematical side of GR, viewed from the lens of differential geometry and analysis.",https://events.umich.edu/event/119406,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
117733-21839902,"2024-03-06 10:00:00","2024-03-06 23:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117201-21838818,"2024-03-06 11:00:00","2024-03-06 12:00:00","`Puncture' stability for the (co)homology of mapping class groups","Rita Jiménez Rolland (UNAM Oaxaca)",Presentation,"In this talk, we will consider the mapping class group of a compact surface with n punctures, and its pure subgroup consisting of mapping classes that fix the punctures pointwise. We will describe two stability phenomena that the (co)homology of these families of groups (indexed by the number n of punctures) exhibit. When the surface has non-empty boundary, the `puncture' homological stability of the family of mapping class groups is closely related with the representation stability of the sequence of homology groups of the pure mapping class groups. If time permits, we will explain this relation and how it could be used to obtain new results.",https://events.umich.edu/event/117201,"East Hall","Pillsbury Room","East Hall",,Mathematics,"Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
117318-21841896,"2024-03-06 15:00:00","2024-03-06 16:00:00","Student CA Seminar: Commutative algebra in the Verlinde category","Karthik Ganapathy","Workshop / Seminar","I'll define the Verlinde category, which is a novel tensor category in characteristic p > 0 whose objects cannot be realized as vector spaces in a precise sense. One can still make sense of commutative rings in the Verlinde category, with the added challenge that one cannot really talk about elements in the ring. We will see that, like in the category of vector spaces, the Hilbert's basis theorem holds, i.e., finitely generated algebras are noetherian, a result due to Venkatesh.",https://events.umich.edu/event/117318,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
119549-21842999,"2024-03-06 15:00:00","2024-03-06 15:50:00","Student Number Theory: A brief introduction to the Langlands correspondence","Kaya Lakein","Workshop / Seminar","In this talk, we will motivate and introduce the Langlands correspondence (in vague terms). We will begin by defining Hasse-Weil L-functions from a point-counting perspective, before seeing how we can think of them as arising from Galois representations. To see how these constructions might be related to automorphic representations, we will begin by considering the relationship between elliptic curves and cuspidal Hecke eigenforms described by the modularity theorem. We will then think about how to define L-functions for automorphic representations more generally, and how they may relate to Hasse-Weil L-functions. Finally, we will use Langlands’ formalism around L-functions of automorphic representations to think about a relationship between automorphic representations of different groups, as formulated in the functoriality conjecture.",https://events.umich.edu/event/119549,"East Hall",5822,"East Hall",,Mathematics,"Student Number Theory Seminar - Department of Mathematics
Department of Mathematics"
115967-21835950,"2024-03-06 16:00:00","2024-03-06 17:30:00","Algebraic Geometry Seminar: Constructible exceptional bundles on P^3","Ben Gould (U. Michigan)","Workshop / Seminar","Exceptional vector bundles are a class of rigid bundles commonly found on Fano varieties with close connections to geometry and homological algebra. Foundational results of Drezet and Le Potier from the 1980s show that on the projective plane exceptional bundles have a deep and elaborate relationship with stable bundles in general. In this talk I will explore how these results in some ways extend and in other ways fail to extend to three-dimensional projective space, and discuss several interesting open problems concerning exceptional bundles.",https://events.umich.edu/event/115967,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
119340-21842588,"2024-03-06 16:00:00","2024-03-06 17:00:00","DCMB / CCMB Weekly Seminar featuring Jeff Vierstra, PhD","High-resolution mapping of the human regulatory genome structure and function","Lecture / Discussion","Abstract:
Transcription regulatory regions harbor the majority of human disease-associated sequence variants. However, our understanding of the impact of regulatory DNA variation is severely limited by the difficulty of precisely assigning the functional contribution of individual nucleotides to phenotypic outcomes. My talk will focus of on my groups efforts to systematically map human regulatory DNA and make use naturally occurring human genetic variation across large cohorts of distinct individuals and cell-types to gain mechanistic insights into regulatory DNA function.
Short Bio:
My group focuses on the development of both experimental and computation approaches better understand the structural and functional architecture of genome-encoded regulatory programs and building tools to manipulate the non-coding genome for therapeutic purposes. Major areas of my ongoing research include (i) development of both molecular and computation tools for the per-nucleotide mapping of the structure and function within individual regulatory elements, (ii) defining the link between human regulatory genetic variation and trait variation to gain mechanistic insights into how genes are normally regulated and disregulated in disease, and (iii) characterizing and decoding regulatory DNA elements that encode cell-identity and differentiation programs. I obtained my BSc in Genetics and Computer Science at the University of Wisconsin, and my PhD at the University of Washington-Seattle. In 2006, I became one of the founding investigators at the non-profit Altius Institute of Biomedical Sciences located in Seattle, WA.
https://umich-health.zoom.us/j/93929606089?pwd=SHh6R1FOQm8xMThRemdxTEFMWWpVdz09",https://events.umich.edu/event/119340,"Palmer Commons","Forum Hall (and Room 1122 at NCRC #520)","Palmer Commons",,Mathematics,"DCMB Seminar Series"
115726-21835436,"2024-03-06 16:00:00","2024-03-06 17:30:00","Geom/Top RTG Seminar: On classifying spaces of mapping class groups","Rita Jiménez Roland (UNAM - Oaxaca)","Workshop / Seminar","Given a discrete group G and a family F of subgroups of G there is a G-CW complex that classifies G-CW complexes with isotropy contained in the family F. Such space is unique up to G-equivariant homotopy and is often called the classifying space of G for the family F. For the trivial family it is the universal cover of a K(G,1) space, and more generally, classifying spaces for families play an important role in the classification of manifolds with a given fundamental group G. In this talk, we will introduce these notions and survey what is known about classifying spaces for some families of subgroups of the mapping class group of an orientable surface of finite type. Time permitting, we will discuss recent joint work with Porfirio León Álvarez and Luis Jorge Sánchez Saldaña in this topic.",https://events.umich.edu/event/115726,"East Hall",3866,"East Hall",,Mathematics,"RTG Seminar on Geometry, Dynamics and Topology - Department of Mathematics
Department of Mathematics"
118756-21841568,"2024-03-07 16:00:00","2024-03-07 17:00:00","Artin's axioms 2","Jonghyun Lee","Workshop / Seminar",TBA,https://events.umich.edu/event/118756,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Learning Seminar - Department of Mathematics
Department of Mathematics"
118092-21840501,"2024-03-07 16:00:00","2024-03-07 17:00:00","Commutative Algebra Seminar: On lengths of $\mathbb{F}_2[x,y,z]/(x^{d_1}, y^{d_2},z^{d_3}, x+y+z)$","Sridhar Venkatesh (UMich)","Workshop / Seminar","While the vector space dimension of the ring $k[x_1, \dots, x_n]/(x_1^{d_1}, \dots, x_n^{d_n})$ can easily be calculated as $\prod_{i=1}^n d_i$, adding in an additional ideal generator $x_1+\dots+x_n$ greatly complicates the problem. In this talk, I will present a formula for the vector space dimension of $\mathbb{F}_2[x,y,z]/(x^{d_1}, y^{d_2},z^{d_3}, x+y+z)$ when $d_1,d_2,d_3$ all lie between successive powers of $2$. Combining this with results of Chungsim Han, we get a complete description of the vector space dimension of $\mathbb{F}_2[x,y,z]/(x^{d_1}, y^{d_2},z^{d_3}, x+y+z)$ for any $d_1,d_2,d_3$. This is joint work with Fiona Han, Jenny Kenkel, Daniel Li, and Ashley Wiles (in fact, this came out of a Winter 2023 LoG(M) project done by Fiona, Daniel and Ashley, where Jenny and I were the mentors).",https://events.umich.edu/event/118092,"East Hall",3088,"East Hall",,Mathematics,"Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
118749-21841562,"2024-03-07 16:00:00","2024-03-07 17:00:00","Differential Equations Seminar: Generic Naked Singularities in Vaidya Spacetimes","James Wheeler, UMICH Mathematics","Workshop / Seminar","The incoming Vaidya spacetimes are perhaps the simplest toy models for the dynamical formation of a Schwarzschild black hole from nonsingular initial conditions, arising from the collapse of a spherically symmetric cloud of null dust. I'll discuss the structure of these spacetimes and demonstrate, via the analysis of a simple ODE, that they can also exhibit the formation of naked singularities, singularities visible from infinity, accompanying the black hole provided only that the null dust accumulates slowly. More pointedly, I'll demonstrate that there is a sense in which the emergence of naked singularities is generic within this class of spacetimes. This observation is of note for the weak cosmic censorship conjecture, a fundamental postulate as to the nature and extent of solutions to the Einstein equations when coupled to ""reasonable"" matter.",https://events.umich.edu/event/118749,"East Hall",4088,"East Hall",,Mathematics,"Differential Equations Seminar - Department of Mathematics
Department of Mathematics"
119607-21843065,"2024-03-07 16:00:00","2024-03-07 16:50:00","Student Dyn/Geo/Top: Random Hyperbolic Surfaces with Long Boundaries","Henry Talbott","Workshop / Seminar","In this talk, I’ll discuss properties of random hyperbolic surfaces with long boundaries. I’ll first talk about what a random surface means in this context, and introduce hyperbolic moduli spaces. I’ll then explain how the ‘spine graph construction’ allows us to relate random hyperbolic surfaces to random graphs, before briefly discussing why this relation works and what we can use it to prove.",https://events.umich.edu/event/119607,"East Hall",2866,"East Hall",,Mathematics,"Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
114767-21833582,"2024-03-08 15:00:00","2024-03-08 16:00:00","AIM Seminar: Understanding the deformation of granular matter and its implications for granular locomotion","Hongyi Xiao, Mechanical Engineering, University of Michigan","Lecture / Discussion","Abstract: Granular matter, being an assembly of discrete particles, has complex mechanical behaviors emerging from the interactions of these particles, which often have a disordered yet non-trivial spatial arrangement. Unlike crystalline materials, the packing structure in a disordered material is often hard to describe mathematically, which prohibits us from understanding the deformation from a structure-property point of view. In this presentation, I will first present experimental results of the deformation of a layer of granular particles floating at an air-oil interface, through which I can demonstrate the elasto-plastic nature of deformation in the quasi-static regime. Based on the experimental results, a machine learning-based modeling framework was developed based on the interplay between elasticity, packing structure, and quasi-localized rearrangements of particles. The model can capture a ductile-to-brittle transition observed in the experimental system due to the change of particle properties.
In the second part of the talk, I will demonstrate the implications of the complex mechanical behaviors of granular materials for locomotion. In this problem, granular matter can be considered as a soft and yielding medium that interacts with a deforming body. I will show experimentally that a scallop-like swimmer with reciprocally flapping wings generates locomotion in granular matter, which is often not possible in Newtonian liquids at low Reynolds numbers. We use X-ray imaging and discrete element method simulations to reveal the microscopic picture of how the wings interact with surrounding particles. The locomotion is enabled by a prolonged hysteresis in the material response that originates from a combination of jamming-induced material rigidity and plastic deformation of the free surface. Cooperative effects are observed when the two wings are in close proximity, which potentially involves interaction of zones with jammed particles as well as heap building on the free surface.
Contact: Silas Alben",https://events.umich.edu/event/114767,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
119597-21843052,"2024-03-08 15:00:00","2024-03-08 16:00:00","Compactification of the Hurwitz Scheme","Ben Baily","Workshop / Seminar","We are motivated by the following problem: which curves are d-sheeted covering spaces of the projective line? We discuss the moduli space of d-sheeted coverings, the *Hurwitz Scheme,* together with a particular compactification due to Mumford and Harris. This compactification, and its relationship to the compactification of the moduli space of genus g curves, allows us to use graph-theoretic tools to help determine whether certain general curves are d-sheeted coverings of P^1.",https://events.umich.edu/event/119597,"East Hall",4088,"East Hall",,Mathematics,"Student Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
118645-21841345,"2024-03-08 15:00:00","2024-03-08 16:00:00","The deep locus in a cluster variety","David E Speyer, University of Michigan","Workshop / Seminar","Cluster varieties are geometric objects corresponding to cluster algebras; they have many open subsets called cluster tori. These tori cover almost all of the cluster variety, but not quite all of it; the ""deep locus"" is the part of the cluster variety which is not in any cluster torus. In joint work with Marco Castronovo, Mikhail Gorsky and José Simental Rodríguez, we conjecture a description of the deep locus, and prove it for braid varieties on 2 and 3 strands. In this talk, I will explain our conjecture, and I will make clear what combinatorial problem we'd need to solve in order to prove this result for all braid varieties. I will not assume that the audience has seen cluster varieties or braid varieties before and, indeed, I hope that this talk will serve as a good introduction to those topics.",https://events.umich.edu/event/118645,"East Hall","East Hall 4096","East Hall",,Mathematics,"Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
119582-21843037,"2024-03-08 16:00:00","2024-03-08 17:00:00","GEOMETRY SEMINAR:Applying diophantine conditions towards entropy and some number theoretical applications of the Einsiedler-Lindenstrauss theorem","Asaf Katz and Prasuna Bandi","Workshop / Seminar","In the first part of the lecture, Asaf will describe a measure classification result of Einsiedler-Fish, showing how one can use diophantine conditions in order to achieve positive entropy for action of a polynomial non-lacunary semigroup on the one-torus.
In the second part, Prasuna will discuss some applications of the Einsiedler-Lindenstrauss measure classification theorem in number theory.",https://events.umich.edu/event/119582,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics"
118502-21841154,"2024-03-09 10:30:00","2024-03-09 11:30:00","Saturday Morning Physics | The Many Facets of Glass","Professor John Kieffer, Department of Materials Science and Engineering (U-M)",Presentation,"Join us in person or via live stream: https://youtu.be/mvjBPBJQVss
Glass has been used for many applications, ranging from arrow heads to optical fibers, and as much as humans have shaped glass to serve these purposes, glass has shaped humanity. However, there remains so much mystery about the amorphous state of matter. Glass is not considered a stable form of matter and yet, it is durable and lasts for millennia.
This presentation provides an overview of what makes glass so unique as a material, the historical role it has played in advancing culture and technology based on its physical properties, and the knowledge we have to date as to what causes glass formation.",https://events.umich.edu/event/118502,"Weiser Hall","170 & 182","Weiser Hall",,Mathematics,"Saturday Morning Physics
Department of Astronomy
Department of Physics
LSA AEM
Applied Physics
LSA Biophysics
Undergrad Physics Events"
119599-21843054,"2024-03-11 00:00:00","2024-03-11 23:00:00","Latinx Research Week 2024",,"Conference / Symposium","Puentes is excited about its upcoming Latinx Research Week (LRW). Latinx Research Week is an interdisciplinary, conference-style series of events that we host annually on campus to uplift research being conducted by Latinx staff, faculty, and students, as well as research relevant to Latinx populations. This year Latinx Research Week will be held on March 11th - 14th in the Michigan Union. In 2023, we were thrilled to host 16 research sessions, allocate space for over 70 presenters, and welcome over 300 attendees across our events. We hope to see an even greater turn out this year.
he theme for Latinx Research Week 2024 is Illuminating Familismo. Familismo is a psychological construct as well as a protective Latinx cultural value that emphasizes the importance of family support, loyalty, and honor. Through our interdisciplinary program, we hope attendees will reflect on, interrogate, and reimagine how the academy can be transformed to acknowledge, welcome, and illuminate both our biological and chosen familial relationships. In past years, we have seen spouses, partners, siblings, parents, children, and members of the larger Latinx community attend Latinx Research Week in support of their presenting family members, thus reimagining what an academic conference could and should look like. Additionally, we have seen other families in attendance: families of co-workers, cohort-mates, best friends, and lab families to name a few. We recognize that many members of the Puentes familia may be far from home but have still chosen to plant roots here and create meaningful communities of chosen family members at UM. We hope that our curated program will illuminate the importance of familismo and encourage attendees to imagine how we can transform academic spaces into more inclusive spaces that honor our families, chosen or otherwise, and the ways they have supported our academic journeys. Latinx Research Week 2024: Illuminating Familiso highlights the many ways our families motivate, inspire, encourage, humanize, and uplift us as we conduct groundbreaking work in our respective fields.",https://events.umich.edu/event/119599,"Michigan Union","Pendleton, Rogel Ballroom, Anderson ABCD","Michigan Union",,Mathematics,"Puentes
Office of Academic Multicultural Initiatives (OAMI)
School of Education
School of Social Work
Rackham Graduate School
Ecology and Evolutionary Biology
Department of Physics
CEW+
Romance Languages & Literatures
Gerald R. Ford School of Public Policy
National Center for Institutional Diversity
Climate and Space Sciences and Engineering
Department of History
Multi Ethnic Student Affairs - MESA
Department of Linguistics
Applied Physics
Department of Psychology
Department of Chemistry
Office of Diversity, Equity & Inclusion
School of Social Work Diversity Equity and Inclusion
School of Education Center for the Study of Higher and Postsecondary Education
SEAS DEI Office"
117733-21839931,"2024-03-11 12:00:00","2024-03-11 13:00:00","Up to $50,000 Grant For Student Sustainability Projects","Planet Blue Student Innovation Fund and The Social and Environmental Sustainability grant.",Meeting,"The Student Sustainability Coalition is awarding up to $50,000 for student driven projects that enhance sustainability or in some instances social sustainability for the University of Michigan's campus community. Attend grant information sessions, email, or check out our webpage to learn more!",https://events.umich.edu/event/117733,"Off Campus Location",,Virtual,,Mathematics,"Student Sustainability Coalition"
117829-21840081,"2024-03-11 15:00:00","2024-03-11 16:00:00","RTG NT: Families of CM forms","Yu-Sheng Lee","Workshop / Seminar","Abstract: Given a Hecke character of a CM field, the automorphic induction of which to the underlying totally real subfield gives a HIlbert modular form with complex multiplication. By the work of Hida and Tilouine the congruences of such forms are governed by the L-value associated with the Hecke character. On the other hand, the Jacquet-Langlands lift of these modular forms to a quaternion algebra can be realized a the theta lift of the character to the corresponding unitary group. We will focus on the case when the unitary group is definite and discuss how one can p-integrally normalize the theta lift and the Rallis inner product formula. As a result we obtain a similar statement for the congruences. We will also discuss further arithmetic applications if time permits.",https://events.umich.edu/event/117829,"East Hall",3088,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
116377-21836671,"2024-03-11 16:00:00","2024-03-11 17:00:00","Counting closed geodesics in the moduli space of Outer space: double exponential growth","Ilya Kapovich","Workshop / Seminar","The problem of counting closed geodesics of bounded length, originally in the setting of negatively curved manifolds, goes back to the classic work of Margulis in 1960s about the dynamics of the geodesic flow. Since then Margulis' results have been generalized to many other contexts where some whiff of hyperbolicity is present.
Thus a 2011 result of Eskin and Mirzakhani shows that for a closed hyperbolic surface S of genus $g\ge 2$, the number $N(L)$ of closed Teichmuller geodesics of length $\le L$ in the moduli space of $S$ grows as $e^{hL}/(hL)$ where $h=6g-6$. The number $N(L)$ is also equal to the number of conjugacy classes of pseudo-Anosov elements $\phi$ in the mapping class group $MCG(S)$ with $\log\lambda(\phi)\le L$, where $\lambda(\phi)>1$ is the ``dilatation"" or ``stretch factor"" of $\phi$.
We consider an analogous problem in the $Out(F_r)$ setting, for the action of the outer automorphism group $Out(F_r)$ of the free group $F_r$ of rank $r$ on a ``cousin"" of the Teichmuller space, called the Culler-Vogtmann Outer space. In this context being a ``fully irreducible"" element of $Out(F_r)$ serves as a natural counterpart of being pseudo-Anosov. Every fully irreducible $\phi\in Out(F_r)$ acts on the Outer space as a loxodromic isometry with translation length $\log\lambda(\phi)$, where again $\lambda(\phi)$ is the stretch factor of $\phi$. We estimate the number $N_r(L)$ of fully irreducible elements $\phi\in Out(F_r)$ with $\log\lambda(\phi)\le L$. The number $N_r(L)$ can also be interpreted as the number of homotopy classes of closed “contracting"" geodesics in the moduli space of the Outer space. We prove, for $r\ge 3$, that $N_r(L)$ grows \emph{doubly exponentially} in $L$ as $L\to\infty$, in terms of both lower and upper bounds. This result reveals new behavior not present in classic hyperbolic dynamical systems. The talk is based on a joint paper with Catherine Pfaff.",https://events.umich.edu/event/116377,"East Hall",3096,"East Hall",,Mathematics,"Complex Analysis, Dynamics and Geometry Seminar - Department of Mathematics
Department of Mathematics"