Identifier,"Start Date / Time","End Date / Time",Title,Subtitle,Type,Description,Permalink,"Building Name",Room,"Location Name",Cost,Tags,Sponsors
112627-21829202,"2023-11-21 14:30:00","2023-11-21 15:45:00","RTG Number Theory: Theta correspondence, Hecke algebra and Springer correspondence","Jialiang Zou","Workshop / Seminar","Abstract: In this talk, we consider the finite field theta correspondence between principle series. Joint with Jiajun Ma and Congling Qiu, we explicitly describe this correspondence by analyzing the relevant Hecke algebra bimodules and applying a deformation argument. Joint with Jiajun Ma and Congling Qiu, Zhiwei Yun, we geometrized the whole picture. Consequently, we obtained a relation between the Springer correspondence and theta correspondence.",https://events.umich.edu/event/112627,"East Hall",4096,"East Hall",,Mathematics,"RTG Seminar on Number Theory - Department of Mathematics
Department of Mathematics"
114308-21832644,"2023-11-21 16:00:00","2023-11-21 17:00:00","Differential Equations Seminar: Stable big bang singularity formation in general relativity","Todd Oliynyk (Monash University)","Workshop / Seminar","Since the 1920's, it has been known that the spatially homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetimes generically develop curvature singularities in the contracting time direction along spacelike hypersurfaces, known as big bang singularities, both in vacuum and for a wide range of matter models. For many years, it remained unclear if the big bang singularities were physically relevant. It was thought by some that big bang singularities were due to the unphysical assumption of spatial homogeneity and that they would disappear in non-homogenous spacetimes, or in other words, big bang singularities were unstable under nonlinear perturbations as solutions to the Einstein field equations. A partial resolution to this situation came in 1967 when Hawking established his singularity theorem that guarantees a cosmological spacetime will be geodesically incomplete for a large class of matter models and initial data sets, including highly anisotropic ones. While Hawking's singularity theorem guarantees that cosmological spacetimes are geodesically incomplete (i.e. at least one observer will experience something pathological at a finite time in the past) for a large class of initial data sets, it is silent on the cause of the geodesic incompleteness. It has been widely anticipated that the geodesics incompleteness is due to the formation of curvature singularities, and it is an outstanding problem in mathematical cosmology to rigorously establish the conditions under which this expectation is true and to understand the dynamical behaviour of cosmological solutions near singularities.
In this talk, I will begin by introducing the FLRW and Kasner solutions of the Einstein-scalar field equations, which are exact, spatially homogeneous solutions that play a distinguished role in the analysis of big bang singularities. After briefly providing context for the FLRW and Kasner solutions in the historical development of the field of cosmology,
I will define what it means for a FLRW/Kasner big bang singularity to be stable. With this notion in hand, I will then discuss the recent influential FLRW and Kasner big bang stability proofs of Rodnianski-Speck and Fournodavlos-Rodnianski-Speck. One aspect of these stability results that I will pay particular attention to is their global nature. To conclude the talk, I will discuss some recent work done in collaboration with Florian Beyer where we improve the Rodnianski-Speck FLRW big bang stability result by establishing that the FRLW big bang is locally stable, which is a significantly stronger notion of stability with important physical consequences that I will briefly discuss. Time permitting, I will also briefly discuss more recent work with Florian Beyer on the stability of big bang singularities when relativistic fluids are present.",https://events.umich.edu/event/114308,"East Hall",3866,"East Hall",,Mathematics,"Differential Equations Seminar - Department of Mathematics
Department of Mathematics"
115477-21834877,"2023-11-27 16:00:00","2023-11-27 17:00:00","Student Combinatorics: Vandermonde matrix, Cauchy matrix, and Cauchy identity","Dawei Shen","Workshop / Seminar","We first present a combinatorial bijective proof of the Vandermonde determinant. Then, we present a combinatorial bijective proof of the Cauchy determinant. Finally, we show that the Cauchy identity is an easy corollary of the Cauchy determinant.",https://events.umich.edu/event/115477,"East Hall",3866,"East Hall",,Mathematics,"Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
110617-21825166,"2023-11-27 16:15:00","2023-11-27 17:30:00","GLNT: Root Number Correlation Bias of Fourier Coefficients of Modular Forms","Nina Zubrilina (Princeton)","Workshop / Seminar","In a recent machine learning based study, He, Lee, Oliver, and Pozdnyakov observed a striking oscillating pattern in the average value of the P-th Frobenius trace of elliptic curves of prescribed rank and conductor in an interval range. Sutherland discovered that this bias extends to Dirichlet coefficients of a much broader class of arithmetic L-functions when split by root number.
In my talk, I will discuss this root number correlation bias when the average is taken over all weight k modular newforms. I will point to a source of this phenomenon in this case and compute the correlation function exactly.",https://events.umich.edu/event/110617,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
111187-21826174,"2023-11-27 17:00:00","2023-11-27 18:00:00","Commutative Algebra Seminar: Singularities on limits of divisors along finite covers.","Seungsu Lee (UMich)","Workshop / Seminar","One of the major questions over a field of mixed characteristics is, ""Is there a divisor D such that the pair (R, D) is BCM-regular when R is a splinter?"" Inspired by this, we introduce compatible systems of divisors on finite covers of R, which have data of divisors on all finite covers of the ring. With this, we will define +-test/adjoint ideals for the system of divisors, and discuss the behavior of the +-test ideals including the inverse of adjunction. This is a joint work with Karl Schwede.",https://events.umich.edu/event/111187,"East Hall","EH 3096","East Hall",,"Mathematics
seminar","Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
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
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
115480-21834879,"2023-11-29 14:30:00","2023-11-29 16:00:00","Learning Seminar in Algebraic Combinatorics: Canonical form of a convex polytope via its dual volume","Yucong Lei","Workshop / Seminar","The main goal of this talk is to introduce a method to compute the canonical form of a convex polytope by computing the volume of its polar dual polytope. We will first define the notion of a dual polytope and then compute the volume in a concrete example. Then we will give a proof that the dual volume actually gives the canonical form of the original convex polytope. Finally, we will introduce a more efficient way to compute the dual volume when the polytope has many vertices but few sides, via the Filliman Duality, which roughly says the volume of the polytope can be obtained from triangulating its dual.",https://events.umich.edu/event/115480,"East Hall",4088,"East Hall",,,"Learning Seminar in Algebraic Combinatorics - 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
seminar","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
Talk
Undergraduate Students","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"
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
seminar
Talk","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"
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",,"Graduate Students
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"
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"
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"
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"
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",,"AEM Featured
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",,"AEM Featured
Mathematics","Colloquium Series - Department of Mathematics
Department of Mathematics"
115949-21835876,"2024-01-16 16:00:00","2024-01-16 17:30:00","Functional MRI Speaker Series","with Dr. Caterina Gratton","Lecture / Discussion","Title: Gaining Precision: Studying Individuals to Provide New Insights into Human Brain Networks and their Role in Control
Abstract: Different regions of the brain interact with one another through large-scale networks. These network interactions are important to many complex processes, including goal-directed control. In my lab, we study large-scale network organization in humans and the principles by which it can vary -- and how these variations contribute to control functions and their breakdown. In the presentation, I will review a sampling of recent studies from our lab investigating forms of variation in large-scale networks within and across people. I will then discuss how these variations influence our studies of control.
*Light refreshments will be served.
*Please take the Church St. elevator to the 4th floor.",https://events.umich.edu/event/115949,"East Hall",4464,"East Hall",,"Biosciences
Brain
Cognitive Neuroscience
Imaging
Neuroimaging
Neuropsychology
Neuroscience
Psychology","Functional MRI Lab
Department of Psychology"
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
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
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
seminar","Student Commutative Algebra 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
seminar
Talk","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",,"AEM Featured
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",,"Graduate Students
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"
117244-21838906,"2024-01-23 13:00:00","2024-01-23 15:00:00","Pop Up Opportunity Hub Coaching",,Other,"Pop up coaching allows you to meet with an Opportunity Hub coach in a space that is convenient to you! This semester, the Opportunity Hub and LSA Psychology are partnering to bring you pop up coaching in the East Hall Psychology Atrium. Pop up coaching is a great opportunity to make meaningful progress toward your professional goals within a shorter period of time; especially if you are a little pressed for time and are looking for on-the-spot support. For example, if you have a grad school, internship, or job application due in a week, drop-in coaching may be ideal. Pop up coaching is also great for students who are looking to try coaching for the first time.
This event is open to ALL students!",https://events.umich.edu/event/117244,"East Hall","Psychology Atrium (North)","East Hall",,"Biopsychology, Cognition, And Neuroscience (Bcn)
Career
Graduate School
Psychology","Psychology Undergraduates
LSA Opportunity Hub"
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
Talk
Undergraduate Students","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"
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
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
117490-21839379,"2024-01-24 14:30:00","2024-01-24 16:00:00","Learning Seminar in Algebraic Combinatorics: Counting faces of polytopes using toric topology","Nir Gadish","Workshop / Seminar","There are deep and subtle relations between the numbers of vertices, edges, triangles, and higher dimensional faces of a polytope. The so-called g-theorem makes these precise by giving necessary and sufficient conditions for an integer vector to be counting the faces of a polytope. In this introductory talk, we'll discuss Stanley's ingenious proof of the g-theorem, which invokes the topology of algebraic varieties. This will take us into the realm of toric varieties, where combinatorics and algebraic geometry intertwine. This bird's-eye view will not include hard algebraic geometry—interesting details will be the subjects of future meetings of the learning seminar.",https://events.umich.edu/event/117490,"East Hall",4088,"East Hall",,,"Learning Seminar in Algebraic Combinatorics - 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
seminar","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",,"AEM Featured
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
seminar","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
seminar
Talk","Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
116995-21838438,"2024-01-26 09:00:00","2024-01-26 10:00:00","Psychology Methods Hour: ""Beyond the cycle: Valid and reliable measurement of ovarian hormone effects in human brain and behavioral research""","Dr. Esmeralda Hidalgo-Lopez, Research Fellow working with Dr. Adriene Beltz",Presentation,"Despite a consistent body of research on the neuroactive effects of reproductive hormones, and the growing attention given to menstrual cycle studies, it is difficult to draw general conclusions about the menstrual cycle’s impact on brain and behavior. This is partially due to the lack of systematic methodology and consistent experimental design across studies, alongside large inter- and intra-individual variability in hormonal patterns. In this Methods Hour, we will delve into the challenges of researching the human menstrual cycle and take a closer look at hormonal suppression (i.e., oral contraceptives) research. Is the menstrual cycle different from other contextual factors (internal and external) that shape the human brain? Is there a correct way of measuring it? How do the biomedical and social sciences benefit from the study of reproductive hormones?",https://events.umich.edu/event/116995,"East Hall",4464,"East Hall",,Psychology,"Department of Psychology
Psychology Methods Hour"
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"
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
Talk
Undergraduate Students","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"
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
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
117948-21840221,"2024-01-31 14:30:00","2024-01-31 16:00:00","Learning Seminar in Algebraic Combinatorics: Toric Varieties from Fans","Mia Smith","Workshop / Seminar","Arising in fields ranging from algebraic geometry to theoretical physics, toric varieties provide a concrete link between combinatorial geometry and algebraic geometry. In this introductory talk, we'll focus our attention on one of the fundamental types of toric varieties, toric varieties constructed from fans.",https://events.umich.edu/event/117948,"East Hall",4088,"East Hall",,,"Learning Seminar in Algebraic Combinatorics - 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
seminar","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
seminar","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
seminar
Talk","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"
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"
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",,"Electrical Engineering and Computer Science
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
Talk
Undergraduate Students","Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
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
seminar","Representation Stability 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
seminar","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"
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"
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
seminar
Talk","Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
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"
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
Talk
Undergraduate Students","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"
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
seminar","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"
116999-21838441,"2024-02-16 09:00:00","2024-02-16 10:00:00","Psychology Methods Hour: ""Uncovering urgency in daily life: Testing a novel method for assessing affect-impulsivity cooccurrence in momentary data""","Janan Mostajabi, Clinical Science Graduate Student",Presentation,"Impulsivity and urgency, a facet of impulsivity defined as the tendency to engage in impulsive behavior when experiencing strong emotions, have wide-ranging implications for physical and mental health. Research on urgency, however, is at a crossroads. On the one hand, there is an extensive body of research on trait self-reports of urgency, suggesting that urgency is a valid and robust construct. On the other hand, more recent work using ambulatory assessment methods has suggested that trait self-reports of urgency are unrelated to state urgency, assessed as the covariance between people’s experienced emotions and impulsivity in the moment. In this Methods Hour talk, we will discuss some of the challenges with assessing urgency in the moment as well as the potential implications of a novel conceptualization of state urgency. Are state and trait urgency different constructs? Are trait measures of urgency truly capturing the theorized construct? How is state urgency best assessed in the moment?",https://events.umich.edu/event/116999,"East Hall",4464,"East Hall",,Psychology,"Department of Psychology
Psychology Methods Hour"
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"
117370-21839225,"2024-02-19 11:00:00","2024-02-19 13:20:00","Foundations and Frontiers Speaker Series","Using Large Language Models to Understand Human Cognition","Lecture / Discussion","Sean Trott is an Assistant Professor at the University of California, San Diego. He holds a joint appointment in Cognitive Science and Computational Social Science. His research focuses on how humans and machines understand language, and makes use of Large Language Models (LLMs) to test hypotheses about human cognition.
UPDATE: Sean Trott will be joining us virtually for this event, the presentation will still take place in East Hall 4448.
Schedule
11:00-11:30 am Foundations Presentation
11:30-11:45 am Q & A
—15 minute pizza break—
12:00-12:50 pm Frontiers Presentation
12:50-1:20 pm Q & A
Presentation Abstract
Foundations: Many debates in Cognitive Science—such as whether certain cognitive capacities are innate, or acquired through specific experiential input—are entrenched and difficult to resolve. A new paradigm attempts to address these debates using Large Language Models (LLMs) to test competing theories of human cognition. In particular, because (most) LLMs are trained on linguistic input alone, they serve as useful baselines: measures of what kinds of behaviors and capacities could in principle emerge purely from exposure to statistical patterns in language. In this talk, I discuss the motivations for such an approach, and briefly survey several examples from the literature. Finally, I discuss the relevant trade-offs and considerations that might inform a researcher's decision about whether to use LLMs in their own research, including: the amount (and quality) of data an LLM has been trained on, issues of construct validity, and multimodal models.
Frontiers: Humans often reason about the mental states of others, even when those mental states diverge from their own. The ability to reason about false beliefs—part of the broader constellation abilities that make up ""Theory of Mind""—is viewed by many as playing a crucial role in social cognition. Yet there is considerable debate about whether this ability comes from. Some theories emphasize the role of innate biological endowments, while others emphasize the role of experience. In this talk, I consider a hypothesis about a specific kind of experience: language. To test this ""language exposure hypothesis"", I use GPT-3, a Large Language Model (LLM) trained on linguistic input alone, and ask whether and to what extent such a system displays evidence consistent with Theory of Mind. The LLM displays above-chance performance on a number of tasks, but also falls short of human performance in multiple cases. I conclude by discussing the implications of these results for the language exposure hypothesis specifically, and for research on Theory of Mind more generally.",https://events.umich.edu/event/117370,"East Hall",4448,"East Hall",,"Free
Language","Weinberg Institute for Cognitive Science"
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
seminar","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",,"Graduate Students
Mathematics
seminar","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",,"AEM Featured
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"
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",,"Graduate School
Mathematics
Talk
Undergraduate Students","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",,"AEM Featured
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",,"Diversity Equity And Inclusion
Education
Mathematics
Teaching And Learning","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",,"Diversity Equity And Inclusion
Education
Mathematics
Teaching And Learning","Learning Community on Inclusive Teaching in Mathematics - Department of Mathematics
Department of Mathematics"
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
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
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"
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",,"AEM Featured
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
seminar","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
seminar
Talk","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"
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"
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",,"Diversity Equity And Inclusion
Education
Mathematics
Teaching And Learning","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
Talk
Undergraduate Students","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"
103185-21836429,"2024-03-06 10:00:00","2024-03-06 16:00:00","Psychology Regalia Fair",,"Fair / Festival","Congrats University of Michigan Psychology Grads!
For all graduating Psych and BCN students, come order your cap & gown, graduation announcements, diploma frame, and official class ring at the Grad Fair.
You can also order your regalia online at herff.ly/umpsych.",https://events.umich.edu/event/103185,"East Hall","Psychology 1st Floor Atrium","East Hall",,"Biopsychology, Cognition, And Neuroscience (Bcn)
Commencement
Graduate Students
Graduation
Psychology
Undergraduate Students","Psychology Undergraduates"
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
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
119595-21843050,"2024-03-06 14:30:00","2024-03-06 16:00:00","Learning Seminar in Algebraic Combinatorics: Chow Group and Cohomology of Simplicial Toric Varieties","Dawei Shen","Workshop / Seminar","We will review the basic theory of Chow groups and study its intersection product for simplicial toric varieties. We will show that the Chow group endowed with the intersection product is isomorphic to the cohomology ring, thus showing various corollaries such as relating Betti numbers and the number of cones in the associated fan. Finally, we will show a description of the cohomology ring in terms of generators and an ideal of relations. We will also prove analogous but stronger statements for nonsingular toric varieties.",https://events.umich.edu/event/119595,"East Hall",4088,"East Hall",,,"Learning Seminar in Algebraic Combinatorics - 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
seminar","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"
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
seminar","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
seminar
Talk","Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
117003-21838444,"2024-03-08 09:00:00","2024-03-08 10:00:00","Psychology Methods Hour: ""Illustrating a Critical Quantitative approach to measurement with MIMIC models""","Dr. Matt Diemer, Combined Program in Education & Psychology Area Chair, Professor of Educational Studies, Faculty Associate in the Research Center for Group Dynamics, ISR",Presentation,"The emerging Critical Quantitative (Crit Quant) perspective is anchored by five guiding principles (i.e., foundation, goals, parity, subjectivity, and self-reflexivity) to mitigate racism and advance social justice. Within this broader methodological perspective, sound measurement is foundational to the quantitative enterprise. Despite the problematic history of measurement, it can be repurposed for critical and equitable ends. MIMIC (Multiple Indicator and Multiple Causes) models are a measurement strategy to simply and efficiently test whether a measure means the same thing and can be measured in the same way across groups (e.g., racial/ethnic and/or gender groups). This talk considers the affordances and limitations of MIMICs for critical quantitative methods, by detecting and mitigating racial, ethnic, gendered, and other forms of bias in items and in measures. Discussion topics will include the affordances of Crit Quant vs QuantCRiT (Quantitative Critical Race Theory) and how Crit Quant and MIMICs do (and don't) detect racism in psychological and social science measures.",https://events.umich.edu/event/117003,"East Hall",4448,"East Hall",,Psychology,"Department of Psychology
Psychology Methods Hour"
117244-21839444,"2024-03-08 13:00:00","2024-03-08 15:00:00","Pop Up Opportunity Hub Coaching",,Other,"Pop up coaching allows you to meet with an Opportunity Hub coach in a space that is convenient to you! This semester, the Opportunity Hub and LSA Psychology are partnering to bring you pop up coaching in the East Hall Psychology Atrium. Pop up coaching is a great opportunity to make meaningful progress toward your professional goals within a shorter period of time; especially if you are a little pressed for time and are looking for on-the-spot support. For example, if you have a grad school, internship, or job application due in a week, drop-in coaching may be ideal. Pop up coaching is also great for students who are looking to try coaching for the first time.
This event is open to ALL students!",https://events.umich.edu/event/117244,"East Hall","Psychology Atrium (North)","East Hall",,"Biopsychology, Cognition, And Neuroscience (Bcn)
Career
Graduate School
Psychology","Psychology Undergraduates
LSA Opportunity Hub"
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"
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"
118024-21840366,"2024-03-11 16:00:00","2024-03-11 17:00:00","ISRMT seminar: Long-time Asymptotics of the KdV Steplike Solutions","Iryna Egorova (B. Verkin Institute for Low Temperature Physics and Engineering & Purdue University)","Workshop / Seminar","The long time asymptotics of the steplike solutions of the KdV equation on the constant backgrounds has long been well studied at the physical level of rigor. This talk will present some recent mathematically rigorous results that refine and justify the above-mentioned asymptotics. We will also compare the efficiency of the two most common methods --- the Nonlinear Steepest Descent and the Inverse Scattering Transform -- for obtaining the soliton asymptotics over a larger space-time domain and for the most general possible class of steplike initial data.",https://events.umich.edu/event/118024,"East Hall","EH 1866","East Hall",,"Mathematics
seminar","Integrable Systems and Random Matrix Theory Seminar - Department of Mathematics
Department of Mathematics"
119964-21843870,"2024-03-11 16:00:00","2024-03-11 17:00:00","Student Combinatorics: An introduction to the m=1 amplituhedron","Amanda Schwartz","Workshop / Seminar","Given a real (k+m) by n matrix Z, there is an induced map from the TNN (k,n)-Grassmannian to the (k,k+m)-Grassmannian. The image of this map is called the amplituhedron A_{n,k,m}(Z). We will discuss some properties of this object when m=1. In particular, we will see how to view the m=1 amplituhedron as a subcomplex of the TNN (k,n)-Grassmannian and also as a complex of bounded faces of a hyperplane arrangement.
Reference: https://arxiv.org/abs/1608.08288",https://events.umich.edu/event/119964,"East Hall",3866,"East Hall",,"Graduate Students","Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
112530-21829084,"2024-03-11 16:15:00","2024-03-11 17:30:00",GLNT,TBA,"Workshop / Seminar",TBA,https://events.umich.edu/event/112530,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
118960-21841951,"2024-03-12 15:00:00","2024-03-12 16:30:00","Functional MRI Speaker Series","with Dr. Scott Langenecker","Lecture / Discussion","Title: Neural, Performance and Trait Mechanisms of and Predictors in Mood Disorders
Abstract: This talk will provide an overview of our work in rumination, trauma, and executive functioning in mood disorders. There will be a specific focus on putative mechanisms leading to risk for mood disorders, exacerbation of or poor treatment response in mood disorders, and predictors of treatment response and course in mood disorders. The work includes samples from early adulthood, adolescence, and late childhood.
*Light refreshments will be served.
*Please take the Church St. elevator to the 4th floor.",https://events.umich.edu/event/118960,"East Hall",4464,"East Hall",,"Biosciences
Brain
Cognitive Neuroscience
Imaging
Neuroimaging
Neuropsychology
Neuroscience
Psychology","Functional MRI Lab
Department of Psychology"
119969-21843875,"2024-03-12 15:00:00","2024-03-12 16:00:00","Student AIM Seminar: Continuous-Variable Quantum Simulation of Interacting Particle Systems","Sam Cochran","Workshop / Seminar","Continuous-variable many-body systems with interactions involving quartic force fields (QFF) play a crucial role in modeling molecular vibrations and their interactions, thereby serving as a bridge between quantum simulations and practical applications in spectroscopy. In this context, the emerging field of continuous-variable quantum computation (CV-QC) offers a novel approach. CV-QC leverages continuous quantum information processing units (qumodes), mapping each continuous degree of freedom in the system being simulated onto a corresponding qumode of the quantum device. This paradigm presents a distinct contrast to digital quantum simulation methods, such as the Zalka-Wiesner method, which discretizes continuous-variable systems for simulation on digital quantum information platforms. In this talk, we will explore the application of CV-QC to both quantum and classical many-body systems, with a focus on systems described by QFFs and classical interacting particle systems.",https://events.umich.edu/event/119969,"East Hall",1068,"East Hall",,Mathematics,"Student AIM Seminar - Department of Mathematics
Department of Mathematics"
115386-21834608,"2024-03-12 16:00:00","2024-03-12 17:00:00","Colloquium Seminar: An introduction to rigid local systems","Michael Groechenig (University of Toronto)","Workshop / Seminar","A representation of a group G is said to be rigid, if it cannot be continuously deformed to a non-isomorphic representation. If G happens to be the fundamental group of a complex projective manifold, rigid representations are conjectured (by Carlos Simpson) to be of geometric origin. In this talk I will outline the basic properties of rigid local systems and discuss several consequences of Simpson‘s conjecture. I will then outline recent progress on these questions (joint work with Hélène Esnault) and briefly mention applications to geometry and number theory such as the recent resolution of the André-Oort conjecture by Pila-Shankar-Tsimerman.",https://events.umich.edu/event/115386,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics"
120037-21843975,"2024-03-12 16:00:00","2024-03-12 17:00:00","Math Undergraduate Seminar: Computational versus Conceptual argumentation","Dhruv Kulshreshtha","Lecture / Discussion","The debate on the validity of conceptual argumentation in mathematics can be traced at least as far back as 1850s Germany -- between computational Berlin-mathematicians like Kummer, Kronecker and Weierstrass, and conceptual Göttingen-mathematicians like Dirichlet, Gauss, and Riemann. This debate intensified with Hilbert's nonconstructive proof of the Basis Theorem leading to Gordan's famous quote: ""This is not Mathematics. This is Theology."" This week's seminar addresses this debate from a History of Mathematics perspective, with the goal of motivating the research program of reverse mathematics.",https://events.umich.edu/event/120037,"East Hall",B743,"East Hall",,"Mathematics
Talk
Undergraduate Students","Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
119959-21843866,"2024-03-12 17:00:00","2024-03-12 18:00:00","Student Analysis Seminar: Power-law distribution in random graphs","Han Le","Workshop / Seminar","Heavy-tailed distributions for random variables have been studied extensively, including, for example, in the study of random matrices, in spin glass models in order to bridge the mean-field spin models and the more realistic ones with short-range interactions. In this talk, we consider heavy-tailed distributions that are governed by a power law density. After covering definitions and several fundamental properties, we will discuss a model for random graphs that was developed in an effort to explain the power law behavior observed in many complex networks in reality.",https://events.umich.edu/event/119959,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
117202-21838819,"2024-03-13 11:00:00","2024-03-13 12:00:00","Interpolation of general affine groups in characteristic 0 via representation stability","Sophie Kriz (Princeton)",Presentation,"I will talk about an embedding of generic FI-modules into a non-semisimple pre-Tannakian category which interpolates the categories of representations of general affine groups which are iterated extensions of representations of general linear groups. I will also discuss an analogous interpolation of representations of semidirect products of symplectic groups with Heisenberg groups.",https://events.umich.edu/event/117202,"East Hall","Pillsbury Room","East Hall",,"Mathematics
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
119970-21843876,"2024-03-13 14:30:00","2024-03-13 16:00:00","Chow Group and Cohomology of Projective Simplicial Toric Varieties","Dawei Shen","Workshop / Seminar","We will show that for projective simplicial toric varieties, the Chow group is isomorphic to its cohomology, thus showing various corollaries such as relating Betti numbers and the number of cones in the associated fan. Finally, we will show a description of the cohomology ring in terms of generators and an ideal of relations.",https://events.umich.edu/event/119970,"East Hall",4088,"East Hall",,,"Learning Seminar in Algebraic Combinatorics - Department of Mathematics
Department of Mathematics"
117319-21839165,"2024-03-13 15:00:00","2024-03-13 16:00:00","Student CA Seminar: Frobenius Splitting for Quotients of Regular Rings","Ben Baily","Workshop / Seminar","Any ring R of characteristic p > 0 is equipped with many natural endomorphisms: for e > 0, the e-th Frobenius map is given by (F^e)(r) = r^(p^e). In this talk, we'll study Hom_R(F^e_*R, R): the R-module of splittings of this map. When R is a regular ring, or more generally a Gorenstein ring, this R-module can be canonically identified with F^e_*R itself. When S = R/I is a quotient of a regular ring, the splittings of F^e: R/I -> R/I can be understood in terms of the ideal I. Using this framework, we demonstrate criteria for determining whether a ring is F-split or F-regular.",https://events.umich.edu/event/117319,"East Hall",1866,"East Hall",,"Mathematics
seminar","Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
119884-21843732,"2024-03-13 15:00:00","2024-03-13 15:50:00","Student Number Theory: Motivating endoscopy via an example with SL(2)","Ram Ekstrom","Workshop / Seminar","Endoscopy arises from the attempt to stabilize the trace formula. The ""stabilization"" of the trace formula is roughly speaking a procedure to make the trace formula more useful for applications and it is an extremely important tool in the Langlands program. I will attempt to motivate the role that endoscopy plays by gently walking through the stabilization of the elliptic regular part of the trace formula for SL(2). During our walkthrough, we will see glimpses of the (elliptic) endoscopic groups, transfer factors, endoscopic transfer of functions, cohomological invariants, etc.—objects which all occur naturally in the theory of endoscopy.",https://events.umich.edu/event/119884,"East Hall",5822,"East Hall",,Mathematics,"Student Number Theory Seminar - Department of Mathematics
Department of Mathematics"
115384-21834606,"2024-03-13 16:00:00","2024-03-13 17:30:00","Algebraic Geometry Seminar: p-adic integration and BPS cohomology","Michael Groechenig (Toronto)","Workshop / Seminar","I will report on joint work in progress with Wyss and Ziegler. The first part of this talk will be a gentle introduction to p-adic integration, focusing on the case of quotient singularities where it is closely related to orbifold cohomology. In the second half we will compute p-adic integrals for singular moduli spaces of objects in certain abelian categories (e.g. representations of a symmetric quiver, meromorphic Higgs bundles, etc) and see that p-adic integration can be related to BPS cohomology arising in the theory of Donaldson-Thomas invariants.",https://events.umich.edu/event/115384,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
114233-21832531,"2024-03-13 16:00:00","2024-03-13 17:00:00","Generalization of Shapley's cooperative value allocation theory via random coalition process","Tongseok Lim, Purdue","Workshop / Seminar","Lloyd Shapley’s cooperative value allocation theory is a central concept in game theory that is widely applied in various fields to assess individual contributions and allocate resources. The Shapley value formula and his four defining axioms form the foundation of the theory.
We interpret the Shapley value as an expectation of a certain stochastic path integral, with each path representing a general coalition process. As a result, the value allocation is naturally extended to all partial coalition states. Furthermore, the new allocation scheme can be readily generalized by path-integrating various edge flows, which we refer to as the f-Shapley value. Finally, by employing Hodge theory on graphs, we show how to compute the stochastic path integral via the graph Poisson equation.",https://events.umich.edu/event/114233,"East Hall",1360,"East Hall",,Mathematics,"Financial/Actuarial Mathematics Seminar - Department of Mathematics
Department of Mathematics"
119952-21843859,"2024-03-13 16:00:00","2024-03-13 17:30:00","RTG GeomTopDyn","Prasuna Bandi","Workshop / Seminar",TBA,https://events.umich.edu/event/119952,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics"
119979-21843891,"2024-03-13 16:00:00","2024-03-13 17:20:00","RTG GeomTopDyn Seminar. Diophantine applications of the Einsiedler-Lindenstrauss theorem","Prasuna Bandi","Workshop / Seminar","We will discuss some applications of the Einsiedler-Lindenstrauss measure classification theorem in number theory.",https://events.umich.edu/event/119979,"East Hall",3866,"East Hall",,Mathematics,"RTG Seminar on Geometry, Dynamics and Topology - Department of Mathematics
Department of Mathematics"
119973-21843884,"2024-03-14 16:00:00","2024-03-14 17:00:00","Commutative Algebra Seminar: Singularities of GL-varieties","Alessandro Danelon (UMich)","Workshop / Seminar","A GL-variety is a reduced affine scheme whose coordinate ring is a polynomial representation that is finitely generated up to the action of the infinite general linear group GL.
Equivalently, GL-varieties are inverse limits of Vec-varieties, functors from the category of finite dimensional vector spaces to reduced affine varieties.
In a joint work with Jan Draisma and Christopher Chiu, taking the perspective of Vec-varieties, we show that the (inverse) limit of the singular loci of a Vec-variety evaluated in dimension n defines a closed Vec-subvariety of “singular points”.
In a forthcoming paper with Andrew Snowden, we show that the GL-variety obtained from these ""singular points"" is actually the locus of singular points of the initial GL-variety, namely, the following loci coincide:
1. The closed GL-variety arising from taking the limit of the singular points in the corresponding Vec-variety.
2. The locus of points where the module of Kähler differential is not flat.
3. The locus of points where the tangent space and tangent cone are not isomorphic.
4. The locus of points that are not formally smooth.
5. The locus of points where there is not an n_0 such that for all n> n_0 an n-jet lift to an n+1-jet.
In this talk, I will present the necessary background and more details about the aforementioned results.",https://events.umich.edu/event/119973,"East Hall",3088,"East Hall",,"Mathematics
seminar","Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"
116183-21836395,"2024-03-14 16:00:00","2024-03-14 17:00:00","Differential Equations Seminar: Phase transition issue of focusing Gibbs measures for Schrödinger-wave systems","Kihoon Seong (Cornell)","Workshop / Seminar","We study the phase transition phenomenon of the singular Gibbs measure associated with the Schrödinger-wave systems, initiated by Lebowitz, Rose, and Speer (1988). In the three-dimensional case, this problem turns out to be critical, exhibiting a phase transition according to the size of the coupling constant. In the weakly coupling region, the Gibbs measure can be constructed as a probability measure, which is singular with respect to the Gaussian free field. On the other hand, in the strong coupling case, the Gibbs measure can not be normalized as a probability measure. In particular, the finite-dimensional truncated Gibbs measures have no weak limit, even up to a subsequence.",https://events.umich.edu/event/116183,"East Hall",EH4088,"East Hall",,Mathematics,"Differential Equations Seminar - Department of Mathematics
Department of Mathematics"
117418-21839278,"2024-03-14 16:00:00","2024-03-14 17:30:00","Simplicial commutative rings","Saket Shah","Workshop / Seminar",TBA,https://events.umich.edu/event/117418,"East Hall",4096,"East Hall",,Mathematics,"Algebraic Geometry Learning Seminar - Department of Mathematics
Department of Mathematics"
119971-21843877,"2024-03-14 16:00:00","2024-03-14 16:50:00","Student Dyn/Geo/Top: Heegaard Floer Homology and Unknotting Number","Nathan Li","Workshop / Seminar","Heegaard Floer homology is a powerful topological invariant of
3-manifolds and knots. The unknotting number is an invariant of knots
that is easy to define but can be difficult to compute. In this talk,
I will review some results that show how Heegaard Floer homology has
been used to determine unknotting numbers of certain knots.",https://events.umich.edu/event/119971,"East Hall",2866,"East Hall",,"Mathematics
seminar
Talk","Student Dynamics/Geometry/Topology Seminar - Department of Mathematics
Department of Mathematics"
114768-21833583,"2024-03-15 15:00:00","2024-03-15 16:00:00","AIM Seminar: A boundary integral equation method for superhydrophobic flow","Kosuke Sugita, Wayne State University","Lecture / Discussion","Abstract: We present the development of a fast and accurate boundary integral equation (BIE) method for the computation of two-dimensional incompressible Stokes flow over superhydrophobic (SH) surfaces. These surfaces are composed of alternating solid portions, grooves, or air pockets, leading to enhanced slip, and are particularly relevant for microfluidic device design. While BIE methods offer advantages in SH flow computations, problems involving SH surfaces present challenges due to flow singularities resulting from complex surface microstructures. These challenges include mixed boundary conditions and geometric corners, causing standard quadrature rules for smooth integrals to suffer from severe accuracy loss. Although often used adaptive mesh refinement can mitigate this issue, it tends to grow the size of discretization significantly, and has difficulties in achieving satisfactory accuracy due to linear system ill-conditioning. To resolve these issues, we combine the Recursively Compressed Inverse Preconditioning (RCIP) method with a scaling technique, kernel-split quadratures, and the Fast Multipole Method. This incorporation yields a fast and accurate numerical scheme for SH flow computations. We demonstrate the effectiveness of our method through several illustrative examples. This research is joint work with Shidong Jiang (Flatiron Institute) and Michael Siegel (New Jersey Institute of Technology).
Contact: Robert Krasny",https://events.umich.edu/event/114768,"East Hall",1084,"East Hall",,Mathematics,"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics
Department of Mathematics"
119032-21842058,"2024-03-15 15:00:00","2024-03-15 16:00:00","Discrete Morse Theory for Symmetric Delta-complexes","Claudia Yun, University of Michigan","Workshop / Seminar","In this talk, we generalize discrete Morse theory to the context of symmetric Delta-complexes. First introduced by Forman, discrete Morse theory is an adaptation of Morse theory for regular CW-complexes. It gives a schematic for collapsing cells in a CW-complex while maintaining the same homotopy type. On the other hand, symmetric Delta-complexes are a generalization of cell-complexes. They are topological spaces built from quotients of standard simplices, and they have played important roles in recent developments of tropical geometry. We generalize various concepts from discrete Morse theory, including discrete Morse functions and acyclic matchings on face posets, and prove parallel theorems for symmetric Delta-complexes. We also apply this new theory to the moduli space of tropical abelian varieties.",https://events.umich.edu/event/119032,"East Hall",4096,"East Hall",,Mathematics,"Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
119965-21843871,"2024-03-15 15:00:00","2024-03-15 16:00:00","The Beauville decomposition","Riku Kurama","Workshop / Seminar","Mukai's seminal work proved that the ""convolution"" with the Poincaré line bundle induces an equivalence of the derived categories of an abelian variety and its dual variety. This equivalence specializes to rational Chow groups of these varieties are isomorphic. We will exploit this structure to exhibit that the rational Chow ring of an abelian variety has an interesting decomposition called the Beauville decomposition.",https://events.umich.edu/event/119965,"East Hall",4088,"East Hall",,Mathematics,"Student Algebraic Geometry Seminar - Department of Mathematics
Department of Mathematics"
119694-21843417,"2024-03-15 16:00:00","2024-03-15 17:30:00","Linguistics Colloquium","Jessi Grieser, University of Michigan Department of Linguistics","Lecture / Discussion","Jessi Grieser is an Associate Professor in the Department of Linguistics at the University of Michigan. Her research focuses on the use of African American Language style in the creation and maintenance of identities which are not necessarily ethnoracial in nature, particularly identities of place and class, with healthy side servings of geosemiotics and the study of language online. Jessi works using the methods of discourse analysis, sociophonetics, and quantitative variationist analysis, and especially the intersections thereof.
TITLE
The Art of Invention
ABSTRACT
This talk addresses one of the thorniest questions facing new graduate students: where do I get good ideas and how do I develop them in useful ways? Using my own career as a case study, I'll talk about successes and failures, and unexpected detours and I'll demonstrate 7 techniques of idea generation which have shaped my work. We'll also talk about what it means to get a Ph.D. more generally and I'll give five tips about how to interact with your work and others in ways that produce scholarly output, can make the process of becoming a Ph.D. straightforward and perhaps, even fun.
Join us in person or virtually",https://events.umich.edu/event/119694,"East Hall",4448,"East Hall",,Free,"Department of Linguistics"
117193-21838808,"2024-03-15 16:00:00","2024-03-15 17:00:00","Twisted rabbit problems in higher degree","Becca Winarski, College of the Holy Cross",Presentation,"In the 1980s Hubbard proposed a compelling question: when composing a polynomial known as the rabbit polynomial with a homeomorphism, the resulting map is equivalent to another (possibly different) polynomial. This question remained open for 25 years until Bartholdi–Nekrashevych solved in in 2006. In this talk, I highlight work with Mukundan and with Lanier that uses the combinatorial topological algorithm developed with Belk, Lanier, and Margalit to solve higher degree analogues of Hubbard's twisted rabbit problem. Our solutions reveal structure within unicritical degree-d polynomials in which the critical point is periodic and introduce accessible questions. This is a joint meeting of the dynamics seminar + the geometry seminar.",https://events.umich.edu/event/117193,"East Hall",3866,"East Hall",,Mathematics,"Geometry Seminar - Department of Mathematics
Department of Mathematics
Complex Analysis, Dynamics and Geometry Seminar - Department of Mathematics"
116805-21838049,"2024-03-18 16:00:00","2024-03-18 17:00:00","Connectedness of moduli spaces: From plane curves to rational maps","Eriko Hironaka",Presentation,"In this talk we describe some ways that fundamental groups and other topological notions have been applied to determine connectedness of moduli spaces. In the 1930s Zariski studied the question of whether the moduli space of plane curves of fixed degree with a certain set of prescribed singularities is connected. He famously showed that plane sextic curves with six cusps and no other singularities is disconnected: the two components corresponding to whether the cusps or not the cusps are in general position or lie on a conic. To prove this, Zariski developed and used tools around fundamental groups and branched coverings, showing that purely topological data can be used to answer geometric questions: the deformability of six cuspidal sextics one to the other. Recently, Milnor asked an analogous question in the realm of rational maps: Is the moduli space of quadratic rational maps of a fixed degree and a prescribed orbit portrait for one of the critical points connected? This problem is still wide open. In this talk we will describe some partial results with a particular focus on the use of topological techniques a la Zariski in this context.",https://events.umich.edu/event/116805,"East Hall",3096,"East Hall",,Mathematics,"Complex Analysis, Dynamics and Geometry Seminar - Department of Mathematics
Department of Mathematics"
120252-21844473,"2024-03-18 16:00:00","2024-03-18 16:00:00","Student Combinatorics: A Geometric Perspective on the q,t-Catalan Numbers","Katie Waddle","Workshop / Seminar","Dyck paths are combinatorial objects enumerated by the Catalan numbers. We can write a generating function for Dyck paths, using q to keep track of the area statistic, and t to keep track of the bounce statistic. Amazingly, while this function is symmetric in q and t, a bijection on Dyck paths that swaps area and bounce continues to elude even the most tenacious combinatistas. Recent work of Guoce Xin and Yingrui Zhang suggests promising results from studying a generalization of Dyck paths. Drawing inspiration from this work, we will discuss how to view Dyck paths as integer points of cones, hoping that the geometric perspective will shed new light on this problem. This is joint work with Matthias Beck, Mitsuki Hanada, Max Hlavacek, John Lentfer, and Andrés Vindas Meléndez.",https://events.umich.edu/event/120252,"East Hall",3866,"East Hall",,"Graduate Students","Student Combinatorics Seminar - Department of Mathematics
Department of Mathematics"
112531-21829085,"2024-03-18 16:15:00","2024-03-18 17:15:00","GLNT: Derived cycles on Shimura varieties and p-adic methods","Keerthi Madapusi (Boston College)","Workshop / Seminar","Abstract: A series of conjectures of Steve Kudla, following classical work of Hirzerbuch-Zagier, Gross-Zagier and Gross-Kohnen-Zagier, predicts that (arithmetic) special cycle classes on certain Shimura varieties can be viewed as Fourier coefficients of automorphic forms in a suitable sense. There is a difficulty even in the formulation of the problem, because the 'natural' definition of cycles associated with degenerate coefficients yields cycles in the wrong degree, an issue that gets rather more severe when one tries to work over the integral model. I'll explain how the theory of virtual fundamental classes for certain derived complete intersection maps gives a systematic fix for this issue, and how recent developments in integral p-adic Hodge theory (joint w. Mathew and Gardner) help to construct such maps.",https://events.umich.edu/event/112531,"East Hall",3088,"East Hall",,Mathematics,"Group, Lie and Number Theory Seminar - Department of Mathematics
Department of Mathematics"
120266-21844488,"2024-03-19 15:00:00","2024-03-19 16:00:00","Student AIM Seminar: Non-parametric estimates for graphon mean-field particle systems","Hongyi Zhou","Workshop / Seminar","Abstract: We consider the graphon mean-field system introduced in the work of Bayraktar, Chakraborty, and Wu. It is the large-population limit of a heterogeneously interacting diffusive particle system, where the interaction is of mean-field type with weights characterized by an underlying graphon function. Through observation of continuous-time trajectories within the particle system, we construct plug-in estimators of the particle density, the drift coefficient, and thus the graphon interaction weights of the mean-field system. Our estimators for the density and drift are direct results of kernel interpolation on the empirical data, and a deconvolution method leads to an estimator of the underlying graphon function. We show that, as the number of particles increases, the graphon estimator converges to the true graphon function pointwisely, and as a consequence, in the cut metric. Besides, we conduct a minimax analysis within a particular class of particle systems to justify the pointwise optimality of the density and drift estimators.",https://events.umich.edu/event/120266,"East Hall",1068,"East Hall",,Mathematics,"Student AIM Seminar - Department of Mathematics
Department of Mathematics"
119698-21843421,"2024-03-19 16:00:00","2024-03-19 17:00:00","Math Undergraduate Seminar: Bombieri-Vinogradov Theorem","Xun Wang","Lecture / Discussion","In this talk, we sketch a proof of the famous Bombieri-Vinogradov theorem and some of the implications.",https://events.umich.edu/event/119698,"East Hall",B743,"East Hall",,"Mathematics
Talk
Undergraduate Students","Math Undergraduate Seminar - Department of Mathematics
Department of Mathematics"
120208-21844223,"2024-03-19 16:00:00","2024-03-19 17:00:00","Sumner Myers Colloqium: Parabolic Towers and the Asymptotic Geometry of the Mandelbrot set","Alex Kapiamba","Workshop / Seminar","Understanding the geometry of the Mandelbrot set has been a central pillar of holomorphic dynamics over the past four decades. Much of its structure is now understood, but a critical question remains unresolved: is the Mandelbrot set locally connected? The first major breakthrough towards this conjecture was achieved by Yoccoz in the nineties, who proved that the Mandelbrot set is locally connected at all parameters which are not infinitely quadratic-like renormalizable. A key ingredient in Yoccoz’s work is the PLY-inequality, which bounds the diameter of certain subsets, called limbs, of the Mandelbrot set. These limbs are naturally labeled by the rational numbers, and the PLY-inequality asserts that the p/q-limb of the Mandelbrot set has size O(1/q). Milnor conjectured that O(1/q2) is the correct scale. For any N ≥ 1, the main result of this thesis is to verify Milnor’s conjecture for all p/q-limbs where a finite continued fraction of p/q has uniformly bounded length. Our strategy relies on careful analysis of the bifurcation of parabolic fixed points; we also further develop some of the classical theory in this area. We introduce parabolic and near-parabolic renormalization operators for maps which have parabolic fixed points of arbitrary multiplier and there perturbations, constructing invariant classes for these operators. We provide an alternative definition to the parabolic towers introduced by Epstein and construct a dynamically natural topology on the space of all parabolic towers. We also study the dynamics of Lavaurs maps, constructing analogues of polynomial external rays for these functions showing that these rays arise as the Hausdorff limits of polynomial external rays.",https://events.umich.edu/event/120208,"East Hall",1360,"East Hall",,Mathematics,"Colloquium Series - Department of Mathematics
Department of Mathematics
Special Events - Department of Mathematics"
120256-21844477,"2024-03-19 17:00:00","2024-03-19 18:00:00","Student Analysis Seminar: Counting Problems & Wave Kinetic Theory","Katja Vassilev","Workshop / Seminar","In this talk, we will learn about Wave Kinetic Theory through the lens of the Cubic Nonlinear Schrodinger Equation. We will begin with an overview of the Wave Kinetic Equation and then talk about how one could prove that it holds. One of the major aspects of proofs used to establish Kinetic Theory is that the problem can be reduced to a counting problem of certain types of mathematical trees/molecules. We focus on the main steps of this reduction and the challenges we may encounter in the counting problem.",https://events.umich.edu/event/120256,"East Hall",4096,"East Hall",,Mathematics,"Student Analysis Seminar - Department of Mathematics
Department of Mathematics"
117203-21838820,"2024-03-20 11:00:00","2024-03-20 12:00:00","Low rank symmetric fusion categories in positive characteristic","Agustina Czenky (Oregon)",Presentation,"In this talk, we look at the classification problem for symmetric fusion categories in positive characteristic. We recall the second Adams operation on the Grothendieck ring and use its properties to obtain some classification results. In particular, we show that the Adams operation is not the identity for any non-trivial symmetric fusion category. We also give lower bounds for the rank of a (non-super-Tannakian) symmetric fusion category in terms of the characteristic of the field. As an application of these results, we classify all symmetric fusion categories of rank 3 and those of rank 4 with exactly two self-dual simple objects.",https://events.umich.edu/event/117203,"East Hall","Pillsbury Room","East Hall",,"Mathematics
seminar","Representation Stability Seminar - Department of Mathematics
Department of Mathematics"
120261-21844482,"2024-03-20 14:30:00","2024-03-20 16:00:00","Learning Seminar in Algebraic Combinatorics: Examples with combinatorial Chow rings","Scott Neville","Workshop / Seminar","In this learning seminar, we have been converting questions about face counts of polytopes into questions about the cohomology of toric varieties. In the case of toric varieties associated to a (nice enough) fan, the cohomology is isomorphic to a combinatorial Chow ring. As their name suggests, the generators and relations of these rings can be described directly from the combinatorics of the fan. We will describe these rings, and give several detailed examples.",https://events.umich.edu/event/120261,"East Hall",4088,"East Hall",,,"Learning Seminar in Algebraic Combinatorics - Department of Mathematics
Department of Mathematics"
120259-21844480,"2024-03-20 15:00:00","2024-03-20 16:00:00","Student CA Seminar - Progress in Big and Small Cohen-Macaulay Modules","Gahl Shemy","Workshop / Seminar","Given a Noetherian local ring (R,m), one might ask whether there exists an R-module M and a system of parameters on R which form a regular sequence on M. Furthermore one might ask whether such M can be chosen to be finitely generated. Modules M satisfying these properties are called Big and Small Cohen-Macaulay modules, respectively. This talk gives a brief historical overview of progress on two major conjectures regarding the existence of Big and Small Cohen-Macaulay Modules.",https://events.umich.edu/event/120259,"East Hall",1866,"East Hall",,Mathematics,"Student Commutative Algebra Seminar - Department of Mathematics
Department of Mathematics"