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PRODID:Mathematics Seminar Calendar
BEGIN:VEVENT
UID:20230322T101959-31520@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Application of KAM Theory in the Fermi-Ulam Models (cont'd)
DESCRIPTION:Speaker\: Jing Zhou, Penn State University\r\nIn this talk I’ll briefly introduce the Fermi acceleration problem and some existing results on the subject. In particular, I’ll discuss how KAM theory has been applied in several variants of the Fermi-Ulam models. I’ll also discuss some open problems in this direction.
LOCATION:C304 Wells Hall
DTSTART:20221219T190000Z
DTEND:20221219T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31520
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BEGIN:VEVENT
UID:20230322T101959-31514@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Combinatorial Aspects of Determinantal Varieties
DESCRIPTION:Speaker\: Anna Weigandt, Massachusetts Institute of Technology\r\nSchubert calculus has its origins in enumerative questions asked by the geometers of the 19th century, such as “how many lines meet four fixed lines in three-space?” These problems can be recast as questions about the structure of cohomology rings of geometric spaces such as flag varieties. Borel’s isomorphism identifies the cohomology of the complete flag variety with a simple quotient of a polynomial ring. Lascoux and Schützenberger (1982) defined Schubert polynomials, which are coset representatives for the Schubert basis of this ring. However, it was not clear if this choice was geometrically natural. Knutson and Miller (2005) provided a justification for the naturality of Schubert polynomials via antidiagonal Gröbner degenerations of matrix Schubert varieties, which are generalized determinantal varieties. Furthermore, they showed that pre-existing combinatorial objects called pipe dreams govern this degeneration. In this talk, we study the dual setting of diagonal Gröbner degenerations of matrix Schubert varieties, interpreting these limits in terms of the “bumpless pipe dreams” of Lam, Lee, and Shimozono (2021). We then use the combinatorics of K-theory representatives for Schubert classes to compute the Castelnuovo-Mumford regularity of matrix Schubert varieties, which gives a bound on the complexity of their coordinate rings. \r\n
LOCATION:C304 Wells Hall
DTSTART:20230109T211000Z
DTEND:20230109T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31514
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BEGIN:VEVENT
UID:20230322T101959-31527@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:G&T Seminar Organizational Meeting
DESCRIPTION:Speaker\: \r\n
LOCATION:C304 Wells Hall
DTSTART:20230110T193000Z
DTEND:20230110T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31527
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31521@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:What analysis, combinatorics, and quilted spheres can tell us about symplectic geometry
DESCRIPTION:Speaker\: Nathaniel Bottman, Max Planck Institute\r\nA central tool for studying symplectic manifolds is the Fukaya category. In this talk, I will describe my program to relate the Fukaya categories of different symplectic manifolds. The key objects are "witch balls", which are coupled systems of PDEs whose domain is the Riemann sphere decorated with circles and points, and "2-associahedra", the configuration spaces of these domains. I will describe applications to symplectic geometry and algebraic geometry, and highlight the role of degenerating families of elliptic PDEs.
LOCATION:C304 Wells Hall
DTSTART:20230110T211000Z
DTEND:20230110T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31521
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BEGIN:VEVENT
UID:20230322T101959-31519@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:A Polytopal View of Schubert Polynomials
DESCRIPTION:Speaker\: Aver St. Dizier, University of Illinois\r\nSchubert polynomials are a family of multivariable polynomials whose product can be used to solve problems in enumerative geometry. Despite their many known combinatorial formulas, there remain mysteries surrounding these polynomials. I will describe Schubert (and the special case of Schur) polynomials with a focus on polytopes. From this perspective, I will address questions such as vanishing of Schubert coefficients, relative size of coefficients, and interesting properties of their support. Time permitting, I'll talk about my current work on generalizing the Gelfand–Tsetlin polytope, and its connections with representation theory and Bott–Samelson varieties.
LOCATION:C304 Wells Hall
DTSTART:20230111T211000Z
DTEND:20230111T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31519
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BEGIN:VEVENT
UID:20230322T101959-31529@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (Passcode: the smallest prime > 100 ): Three uses of semidefinite programming in approximation theory
DESCRIPTION:Speaker\: Simon Foucart, Texas A&M University\r\nIn this talk, modern optimization techniques are publicized as fitting computational tools to attack several extremal problems from Approximation Theory which had reached their limitations based on purely analytical approaches. Three such problems are showcased: the first problem---minimal projections---involves minimization over measures and exploits the moment method; the second problem---constrained approximation---involves minimization over polynomials and exploits the sum-of-squares method; and the third problem---optimal recovery from inaccurate observations---is highly relevant in Data Science and exploits the S-procedure. In each of these problems, one ends up having to solve semidefinite programs.\r\n
LOCATION:C304 Wells Hall
DTSTART:20230112T193000Z
DTEND:20230112T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31529
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BEGIN:VEVENT
UID:20230322T101959-31511@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:The geometry of scalar curvature and mass in general relativity
DESCRIPTION:Speaker\: Demetre Kazaras, Duke University\r\nIn general relativity, the space we inhabit is modeled by a Riemannian manifold. The fundamental restriction this theory places upon spatial geometry is a lower bound on this manifold's scalar curvature. It is an important problem in pure geometry to understand the geometric and topological features of this condition. For instance, if a manifold has positive scalar curvature, what may we conclude about the lengths of its curves, the areas of its surfaces, and the topology of the underlying manifold? I will explain many results (originally proven by Schoen-Yau and Gromov-Lawson) in this direction, and sketch proofs by analyzing objects I call 'spacetime harmonic functions.' Leveraging these new ideas, I will also describe progress on geometric versions of the following questions: How flat is a gravitational system with little total mass? How can we tell when matter will coalesce to form a black hole? \r\n
LOCATION:C304 Wells Hall
DTSTART:20230112T211000Z
DTEND:20230112T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31511
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BEGIN:VEVENT
UID:20230322T101959-31528@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Mathematics of novel materials from atomic to macroscopic scales
DESCRIPTION:Speaker\: Alexander Watson, University of Minnesota\r\nMaterials' electronic properties arise from the complex dynamics of electrons flowing through the material. These dynamics are quantum mechanical and present many surprising phenomena without classical analogues. I will present analytical and numerical work clarifying these dynamics in three novel materials which have attracted intense theoretical and experimental attention in recent years: graphene, the first ``2D'' material, whose electronic properties can be captured by an effective Dirac equation, topological insulators, whose edges host surprising one-way edge currents, and twisted bilayer graphene, an aperiodic material whose properties can be captured by an effective system of Dirac equations with periodic coefficients. I will then present ongoing and future work focused on further clarifying the properties of twisted bilayer graphene, which was recently shown to superconduct when twisted to the ``magic'' twist angle 1 degree.
LOCATION:C304 Wells Hall
DTSTART:20230113T211000Z
DTEND:20230113T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31528
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BEGIN:VEVENT
UID:20230322T101959-31510@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Random matrices and random partitions at varying temperatures
DESCRIPTION:Speaker\: Cesar Cuenca, Harvard University\r\nI will discuss the global-scale behavior of ensembles of random matrix eigenvalues and random partitions which depend on the "inverse temperature" parameter beta. The goal is to convince the audience of the effectiveness of the moment method via Fourier-like transforms in characterizing the Law of Large Numbers and Central Limit Theorems in various settings. We focus on the regimes of high and low temperatures, that is, when the parameter beta converges to zero and infinity, respectively. Part of this talk is based on joint projects with F. Benaych-Georges -- V. Gorin, and M. Dolega -- A. Moll. \r\n
LOCATION:C304 Wells Hall
DTSTART:20230117T211000Z
DTEND:20230117T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31510
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BEGIN:VEVENT
UID:20230322T101959-31524@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Compactifications of Hitchin components
DESCRIPTION:Speaker\: Charles Ouyang, UMass Amherst\r\nHitchin components are natural generalizations of the classical Teichmüller space. In the setting of SL(3,R), the Hitchin component parameterizes the holonomies of convex real projective structures, which are related to hyperbolic affine spheres. By studying Blaschke metrics, which are Riemannian metrics associated to hyperbolic affine spheres, along with their limits, we obtain a compactification of the SL(3,R)-Hitchin component. We show the boundary objects are hybrid structures, which are in part flat metric and in part laminar. These hybrid objects are natural generalizations of measured laminations, which are the boundary objects in Thurston's compactification of Teichmüller space.
LOCATION:C304 Wells Hall
DTSTART:20230118T211000Z
DTEND:20230118T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31524
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BEGIN:VEVENT
UID:20230322T101959-31530@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (Passcode: the smallest prime > 100 ): Low rank approximation for faster optimization
DESCRIPTION:Speaker\: Madeleine Udell, Stanford University\r\nLow rank structure is pervasive in real-world datasets. This talk shows how to accelerate the solution of fundamental computational problems, including eigenvalue decomposition, linear system solves, composite convex optimization, and stochastic optimization (including deep learning), by exploiting this low rank structure. We present a simple method based on randomized numerical linear algebra for efficiently computing approximate top eigendecompositions, which can be used to replace large matrices (such as Hessians and constraint matrices) with low rank surrogates that are faster to apply and invert. The resulting solvers for linear systems (NystromPCG), composite convex optimization (NysADMM), and deep learning (SketchySGD) demonstrate strong theoretical and numerical support, outperforming state-of-the-art methods in terms of speed and robustness to hyperparameters.\r\n\r\n
LOCATION:C304 Wells Hall
DTSTART:20230119T193000Z
DTEND:20230119T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31530
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31518@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Freeness and matrices
DESCRIPTION:Speaker\: March Tian Boedihardjo, ETH Zurich\r\nI will begin by giving some background on Free Probability motivated by the freeness in free groups. I will then demonstrate how Free Probability can be used to obtain a sharp non-asymptotic random matrix estimate for general use. This talk will be concluded by a recent application of our result to the Matrix Spencer Conjecture. Joint work with Afonso Bandeira and Ramon van Handel.
LOCATION:C304 Wells Hall
DTSTART:20230119T211000Z
DTEND:20230119T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31518
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31552@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Lorenz attractor and singular flows: expansivity, entropy, and equilibrium states
DESCRIPTION:Speaker\: Fan Yang, Michigan State University\r\n
LOCATION:C304 Wells Hall
DTSTART:20230120T200000Z
DTEND:20230120T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31552
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31512@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY: Geometric boundary conditions for the Einstein equations and quasi-local mass
DESCRIPTION:Speaker\: Zhongshan An, University of Michigan\r\nThe Einstein equations are the most fundamental equations for spacetimes in general relativity. They relate the geometry (curvatures) of a spacetime with its physical property. When a spacetime has nonempty boundary, it is natural to ask what geometric boundary conditions are well-posed for the Einstein equations. The investigation of geometric boundary conditions both gives rise to interesting geometric PDE problems in differential geometry, and also plays an important role in the study of quasi-local mass for compact spacetimes in general relativity. In this talk, we will discuss geometric boundary conditions for the vacuum Einstein equations, from both the hyperbolic and elliptic aspects. Furthermore, we will talk about applications of these geometric boundary value problems in the construction of quasi-local mass.
LOCATION:C304 Wells Hall
DTSTART:20230123T211000Z
DTEND:20230123T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31512
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31551@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Fostering a Culture of Instructional Development in the Department of Statistics and Probability: Our Journey with First-Year Graduate Teaching Assistants
DESCRIPTION:Speaker\: Vince Melfi, MSU, Jenny Green, MSU, John Keane, MSU\r\nHow do we support graduate students to teach introductory statistics classes, which themselves are undergoing dramatic transformation? In this talk, we will get to engage with\r\nlessons learned and questions still unanswered as we embarked on the journey of developing an instructional mentoring program for the Department of Statistics and Probability.
LOCATION:115 Erickson Hall
DTSTART:20230124T180000Z
DTEND:20230124T193000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31551
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31540@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Stationary measures of the Kardar-Parisi-Zhang equation and their limits
DESCRIPTION:Speaker\: Wlodzimierz Bryc, University of Cincinnati\r\nI will overview recent results of [Corwin and Knizel, 2021] on the existence of stationary measures for the KPZ equation on an interval and [Barraquand and Le Doussal, 2022], [B.-Kuznetsov-Wang-Wesolowski, 2022] who found two different probabilistic descriptions of the stationary measures as a Markov process and as a measure with explicit Radon-Nikodym derivative with respect to the Brownian motion. The Markovian description leads to rigorous proofs of some of the limiting results claimed in [Barraquand and Le Doussal, 2022]. I shall discuss how the stationary measures of the KPZ equation on [0,L] behave at large scale as L goes to infinity which according to [Barraquand and Le Doussal, 2022] depending on the normalization, should correspond to stationary measures of a hypothetical KPZ fixed point on [0,1], to the stationary measure for the KPZ equation on the half-line, and to the stationary measure of a hypothetical KPZ fixed point on the half-line.\r\n\r\nThe talk is based mostly on a joint work with Alexey Kuznetsov (ALEA 2022).
LOCATION:Online (virtual meeting)
DTSTART:20230125T200000Z
DTEND:20230125T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31540
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31525@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:CANCELLED: Symmetric structures in the strong Bruhat order
DESCRIPTION:Speaker\: Yibo Gao, University of Michigan\r\nThe Bruhat order encodes algebraic and topological information of Schubert varieties in the flag manifold and possesses rich combinatorial properties. In this talk, we discuss three interrelated stories regarding the Bruhat order: self-dual Bruhat intervals, Billey-Postnikov decompositions and automorphisms of the Bruhat graph. This is joint work with Christian Gaetz.
LOCATION:C304 Wells Hall
DTSTART:20230125T200000Z
DTEND:20230125T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31525
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31550@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Disability Equity in Mathematics Education: Accessibility, Re-mediation, and CompensationAbstract
DESCRIPTION:Speaker\: Katie Lewis, University of Washington\r\nEquity in mathematics education research has only recently begun to consider students with disabilities. In this talk, I focus specifically on students with mathematics disabilities – students who have a neurological difference in how their brains process numerical information. Prior research on mathematics disabilities (i.e., dyscalculia) has predominantly taken up a deficit frame, documenting the ways in which students with dyscalculia are deficient in terms of speed and accuracy. In my work, I argue that this deficit orientation is problematic, and I offer an alternative. I take up an explicitly anti-deficit framing and draw upon sociocultural learning theories and Disability Studies to orient my work. In this talk I use multiple case studies to explore ideas about accessibility, re-mediation, and compensation across a range of mathematical topics. This anti-deficit work provides an alternative vantage point to understand disability in mathematics education and suggests avenues to work towards equity. I close by considering ways that mathematics education equity research can be in service of and in partnership with the populations that we study. Zoom option: https://msu.zoom.us/j/95059549382 Passcode: PRIME
LOCATION:252 EH
DTSTART:20230125T203000Z
DTEND:20230125T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31550
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31531@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Approximately Finite Dimensional C*-algebras
DESCRIPTION:Speaker\: Lucas Hall, MSU\r\nI’ll tour through the study of finite dimensional C*-algebras and homomorphisms between them, and use this as a basis to define and study approximately finite dimensional (AF) algebras.
LOCATION:C517 Wells Hall
DTSTART:20230130T210000Z
DTEND:20230130T223000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31531
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31559@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY: From homotopy Lie brackets to thick morphisms of supermanifolds and non-linear functional-algebraic duality (NOTE UNUSUAL DAY)
DESCRIPTION:Speaker\: Theodore Voronov, University of Manchester\r\n I will give a motivation for homotopy Lie brackets and the corresponding morphisms preserving brackets "up to homotopy" (more precisely, for L-infinity morphisms and L-infinity algebras), and show how to describe them using supergeometry. So, instead of a single Poisson or Lie bracket, there is a whole sequence of operations with n arguments, n=1,2,3,..., satisfying a linked infinite sequence of identities replacing the familiar Jacobi identity for a Lie bracket; and, instead of a morphism as a linear map mapping a bracket to a bracket, there is a sequence of multi-linear mappings mixing brackets with different numbers of arguments, and, in particular, the binary bracket is preserved only up to an (algebraic) homotopy. Geometrically, such a sequence of multi-linear mappings assembles into one non-linear map of supermanifolds.\r\n\r\nFor the case of homotopy brackets of functions ("higher Poisson" or "homotopy Poisson" structure), this leads us to the question about a natural construction of non-linear mappings between algebras of smooth functions generalizing the usual pull-backs. I discovered such a construction some years ago. These are "thick morphisms" of (super)manifolds generalizing ordinary smooth maps. From a more general perspective, we arrive in this way at a non-linear analog of the classical functional-algebraic duality between spaces and algebras.
LOCATION:C204A Wells Hall
DTSTART:20230131T200000Z
DTEND:20230131T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31559
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31557@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Maximal Chain Descent Orders
DESCRIPTION:Speaker\: Stephen Lacina, University of Oregon\r\nWe introduce a new partial order called the maximal chain descent order on the maximal chains of any finite, bounded poset with an EL-labeling. We prove that the maximal chain descent order encodes via its linear extensions all shellings of the order complex induced by the EL-labeling strictly including the well-known lexicographic shellings. We show that the standard EL-labeling of the Boolean lattice has maximal chain descent order isomorphic to the type A weak order. We also prove that natural EL-labelings of intervals in Young's lattice give maximal chain descent orders isomorphic to partial orders on the standard Young tableaux or standard skew tableaux of a fixed shape given by swapping certain entries. We additionally show that the cover relations of maximal chain descent orders are generally more subtle than one might first expect, but we characterize the EL-labelings with the expected cover relations including many well-known families of EL-labelings.\r\n
LOCATION:Online (virtual meeting)
DTSTART:20230201T200000Z
DTEND:20230201T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31557
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31558@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Profinite groups and infinite Galois theory
DESCRIPTION:Speaker\: Igor Rapinchuk, MSU\r\n
LOCATION:C329 Wells Hall
DTSTART:20230201T200000Z
DTEND:20230201T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31558
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31560@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Potentially orthonormalizable modules
DESCRIPTION:Speaker\: Jie Yang, MSU\r\nI will discuss basics of potentially orthonormalizable modules and some related concepts, which are preliminaries for the theory of Fredholm's determinant of compact operators in non-archimedean setting.
LOCATION:C204A Wells Hall
DTSTART:20230202T190000Z
DTEND:20230202T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31560
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31553@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - Towards Intrinsically Low-Dimensional Models in Wasserstein Space: Geometry, Statistics, and Learning
DESCRIPTION:Speaker\: James Murphy, Tufts University\r\nWe consider the problems of efficient modeling and representation learning for probability distributions in Wasserstein space. We consider a general barycentric coding model in which data are represented as Wasserstein-2 (W2) barycenters of a set of fixed reference measures. Leveraging the Riemannian structure of W2-space, we develop a tractable optimization program to learn the barycentric coordinates when given access to the densities of the underlying measures. We provide a consistent statistical procedure for learning these coordinates when the measures are accessed only by i.i.d. samples. Our consistency results and algorithms exploit entropic regularization of the optimal transport problem, thereby allowing our barycentric modeling approach to scale efficiently. We also consider the problem of learning reference measures given observed data. Our regularized approach to dictionary learning in Wasserstein space addresses core problems of ill-posedness and in practice learns interpretable dictionary elements and coefficients useful for downstream tasks. Applications to image and natural language processing will be shown throughout the talk.
LOCATION:C304 Wells Hall
DTSTART:20230202T193000Z
DTEND:20230202T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31553
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31535@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Free Stein dimension of crossed products by finite groups
DESCRIPTION:Speaker\: Aldo Garcia Guinto, MSU\r\nIn this talk, we will discuss a free probabilistic quantity called free Stein dimension and compute it for a crossed product by a finite group. The free Stein dimension is the Murray-von Neumann dimension of a particular subspace of derivations. Charlesworth and Nelson defined this quantity in the hope of finding a von Neumann algebra invariant. While it is still not known to be a von Neumann algebra invariant, it is an invariant for finitely generated unital tracial *-algebras and algebraic methods have been more successful than analytic ones in studying it. Our result continues this trend, and reveals a formula for the free Stein dimension of a crossed product by a finite group that is reminiscint of the Schreier formula for a finite index subgroups of free groups.
LOCATION:C517 Wells Hall
DTSTART:20230206T210000Z
DTEND:20230206T223000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31535
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31562@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Does the Jones polynomial of a knot detect the unknot? A novel approach via braid group representations and class numbers of number fields.
DESCRIPTION:Speaker\: Amitesh Datta, Princeton University \r\nHow good of an invariant is the Jones polynomial? The question is closely tied to studying braid group representations since the Jones polynomial can be defined as a (normalized) trace of a braid group representation.\r\n\r\nIn this talk, I will present my work developing a new theory to precisely characterize the entries of classical braid group representations, which leads to a generic faithfulness result for the Burau representation of B_4 (the faithfulness is a longstanding question since the 1930s and is equivalent to whether B_4 is a group of 3 x 3 matrices). In forthcoming work, I use this theory to furthermore explicitly characterize the Jones polynomial of all 3-braid closures and generic 4-braid closures. I will also describe my work which uses the class numbers of quadratic number fields to show that the Jones polynomial detects the unknot for 3-braid links - this work also answers (in a strong form) a question of Vaughan Jones.\r\n\r\nI will discuss all of the relevant background from scratch and illustrate my techniques through simple examples.
LOCATION:Online (virtual meeting)
DTSTART:20230207T203000Z
DTEND:20230207T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31562
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31563@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Parabolic Tamari Lattices in Linear Type B
DESCRIPTION:Speaker\: Wenjie Fang, Université Gustave Eiffel\r\nWe study parabolic aligned elements associated with the type-B Coxeter group and the so-called linear Coxeter element. These elements were introduced algebraically in (Mühle and Williams, 2019) for parabolic quotients of finite Coxeter groups and were characterized by a certain forcing condition on inversions. We focus on the type-B case and give a combinatorial model for these elements in terms of pattern avoidance. Moreover, we describe an equivalence relation on parabolic quotients of the type-B Coxeter group whose equivalence classes are indexed by the aligned elements. We prove that this equivalence relation extends to a congruence relation for the weak order. The resulting quotient lattice is the type-B analogue of the parabolic Tamari lattice introduced for type A in (Mühle and Williams, 2019). These lattices have not appeared in the literature before. As work in progress, we will also talk about various combinatorial models and bijections between them. Joint work with Henri Mühle and Jean-Christophe Novelli.
LOCATION:Online (virtual meeting)
DTSTART:20230208T200000Z
DTEND:20230208T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31563
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31567@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Profinite groups and infinite Galois theory
DESCRIPTION:Speaker\: Igor Rapinchuk, MSU\r\n
LOCATION:C329 Wells Hall
DTSTART:20230208T200000Z
DTEND:20230208T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31567
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31539@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Some recent progress in the weak noise theory of the KPZ equation
DESCRIPTION:Speaker\: Yier Lin, University of Chicago\r\nIn this talk, we will study the Freidlin–Wentzell LDP for the KPZ equation using the variational principle. Such an approach goes under the name of the weak noise theory in physics. We will explain how to extract various limits of the most probable shape of the KPZ equation in the setting of the Freidlin–Wentzell LDP. Some future directions will also be discussed at the end. The talk is based on several joint works with Pierre Yves Gaudreau Lamarre and Li-Cheng Tsai.
LOCATION:Online (virtual meeting)
DTSTART:20230208T200000Z
DTEND:20230208T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31539
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31564@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Noncommutative Bohnenblust--Hille inequalities and application to learning the quantum observables
DESCRIPTION:Speaker\: Alexander Volberg, MSU\r\nBohnenblust--Hille inequalities for Boolean cubes have been proven with dimension-free constants that grow sub-exponentially in the degree (Defant—Mastylo—Peres). Such inequalities have found great applications in learning low degree Boolean functions (Eskenazis—Ivanisvili). Motivated by learning quantum observables, a quantum counterpart of Bohnenblust--Hille inequality for Boolean cubes was recently conjectured in Cambyse Rouz\’e, Melchior Wirth, and Haonan Zhang: ``Quantum Talagrand, KKL and Friedgut’s theorems and the learnability of quantum Boolean functions.” arXiv preprint, arXiv:2209.07279, 2022. \r\n\r\nHaonan Zhang and myself prove such noncommutative Bohnenblust--Hille inequalities with constants that are dimension-free and of exponential growth in the degree. As applications, we study learning problems of quantum observables. \r\n\r\n(Speaker will present remotely)
LOCATION:C304 Wells Hall
DTSTART:20230208T211000Z
DTEND:20230208T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31564
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31561@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:AI, ChatGPT, and Teaching
DESCRIPTION:Speaker\: Andy Krause, MSU\r\n
LOCATION:D101 Wells Hall
DTSTART:20230209T160000Z
DTEND:20230209T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31561
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31568@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Banach space over Qp
DESCRIPTION:Speaker\: Peikai Qi, MSU \r\n
LOCATION:C204A Wells Hall
DTSTART:20230209T191000Z
DTEND:20230209T201000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31568
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31569@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - Combining network analysis and persistent homology for classifying behavior of time series
DESCRIPTION:Speaker\: Elizabeth Munch, MSU\r\nPersistent homology, the flagship method of topological data analysis, can be used to provide a quantitative summary of the shape of data. One way to pass data to this method is to start with a finite, discrete metric space (whether or not it arises from a Euclidean embedding) and to study the resulting filtration of the Rips complex. In this talk, we will discuss several available methods for turning a time series into a discrete metric space, including the Takens embedding, $k$-nearest neighbor networks, and ordinal partition networks. Combined with persistent homology and machine learning methods, we show how this can be used to classify behavior in time series in both synthetic and experimental data.
LOCATION:C304 Wells Hall
DTSTART:20230209T193000Z
DTEND:20230209T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31569
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31566@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Foliations and transverse invariant measures from a dynamical systems point of view
DESCRIPTION:Speaker\: Fan Yang, Michigan State University\r\nIn this talk, we will discuss foliations and their transverse invariant measures (i.e., measures on cross-sections that are invariant under the holonomy maps) from a dynamical systems point of view. We will show that for a large family of diffeomorphisms, the unstable foliations admit families of transverse measures that are naturally related to certain probability measures invariant under the dynamics. Given an unstable leaf, we will consider a dynamically defined average that captures its intersection with cross-sections and prove that this averaging will converge exponentially fast to the transverse invariant measures. This is a joint work with Ures, Viana and J. Yang.
LOCATION:C117 Wells Hall
DTSTART:20230209T200000Z
DTEND:20230209T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31566
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31578@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:GAUSS: Construct 3-Manifolds with Bagels
DESCRIPTION:Speaker\: Chen Zhang, MSU\r\nAbstract: Any closed compact 3 manifold admits a Heegaard splitting, which splits the 3 manifold into two handlebodies. In this talk, we will use bagels to illustrate the idea of Heegaard splitting. More specifically, we will use 2 bagels to construct 3 sphere and finite many bagels to construct any 3 manifold. Besides, bagels will be provided during the talk.
LOCATION:C304 Wells Hall
DTSTART:20230213T173000Z
DTEND:20230213T183000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31578
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31523@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Derived cycles on Shimura varieties
DESCRIPTION:Speaker\: Keerthi Madapusi, Boston College\r\nI’ll explain how methods from derived algebraic geometry can be applied to give a uniform definition of special cycle classes on integral models of Shimura varieties of Hodge type, verifying some consequences of Kudla’s conjectures on the modularity of generating series of cycles on Shimura varieties of Hermitian type.
LOCATION:C304 Wells Hall
DTSTART:20230213T200000Z
DTEND:20230213T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31523
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31504@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Title: On the kernel of Witten-Reshetikhin-Turaev quantum representations
DESCRIPTION:Speaker\: Renaud Detcherry, Institut de Mathématiques de Bourgogne \r\n\r\n\r\nAbstract: Witten-Reshetikhin-Turaev SO(3) quantum representations are a family of representations of mapping class groups of surfaces. The family is asymptotically faithful, but each representation has kernel: indeed, r-th powers of Dehn twists are in the kernel of the level r quantum representation.\r\nAn open question is whether the kernel is generated by r-th powers of Dehn twists; we will present partial results on this question, by relating the so-called "h-adic expansion" of quantum representations to Johnson homomorphisms.\r\n\r\n
LOCATION:C304 Wells Hall
DTSTART:20230214T190000Z
DTEND:20230214T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31504
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31574@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:CANCELLED: A Murnaghan-Nakayama formula in quantum Schubert calculus
DESCRIPTION:Speaker\: Frank Sottile, Texas A and M Univeristy\r\nThe Murnaghan-Nakayama formula expresses the product of a\r\nSchur function with a Newton power sum in the basis of Schur\r\nfunctions. An important generalization of Schur functions are\r\nSchubert polynomials (both classical and quantum). For these, a\r\nMurnaghan-Nakayama formula is geometrically meaningful. In\r\nprevious work with Morrison, we established a Murnaghan-Nakayama\r\nformula for Schubert polynomials and conjectured a quantum\r\nversion. In this talk, I will discuss some background and then\r\nsome recent work proving this quantum conjecture. This is joint\r\nwork with Benedetti, Bergeron, Colmenarejo, and Saliola.
LOCATION:C517 Wells Hall
DTSTART:20230215T200000Z
DTEND:20230215T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31574
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31584@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:CANCELLED: Profinite groups and infinite Galois theory
DESCRIPTION:Speaker\: Igor Rapinchuk, MSU\r\n
LOCATION:C304 Wells Hall
DTSTART:20230215T200000Z
DTEND:20230215T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31584
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31585@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Property (Pr) and completed tensor product
DESCRIPTION:Speaker\: Patel Coupek, MSU\r\n
LOCATION:C204A Wells Hall
DTSTART:20230216T191000Z
DTEND:20230216T201000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31585
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31565@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Iwasawa lambda-invariants and Massey products
DESCRIPTION:Speaker\: Peikai Qi, MSU\r\n
LOCATION:C304 Wells Hall
DTSTART:20230220T200000Z
DTEND:20230220T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31565
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31556@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Seiberg-Witten Floer K-Theory and Cyclic Group Actions
DESCRIPTION:Speaker\: Ian Montague , Brandeis University\r\nGiven a spin rational homology sphere equipped with a cyclic group action, I will introduce equivariant refinements of Manolescu's kappa invariant, derived from the equivariant K-theory of the Seiberg--Witten Floer spectrum. These invariants give rise to equivariant relative 10/8-ths type inequalities for equivariant spin cobordisms between rational homology spheres. I will explain how these inequalities provide applications to knot concordance, obstruct cyclic group actions on spin fillings, and give genus bounds for knots in punctured 4-manifolds. If time permits I will explain how these invariants are related to equivariant eta-invariants of the Dirac operator, and describe work-in-progress which provides explicit formulas for the $S^1$-equivariant eta-invariants on Seifert-fibered spaces.
LOCATION:C304 Wells Hall
DTSTART:20230221T190000Z
DTEND:20230221T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31556
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31591@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:The quantum trace for skein algebras of surfaces
DESCRIPTION:Speaker\: Francis Bonahon, MSU\r\nThe quantum trace homomorphism connects two competing quantizations for the $SL_n$-character variety of a surface, consisting of $SL_n$-local systems over the surface. The first quantization is through the $SL_n$-skein algebra, which is intrinsic but difficult to work with. The second quantization is based on a quantization of Thurston-Fock-Goncharov local coordinates, and is algebraically easier to handle but depends on choices. I will focus on the construction of this quantum trace in the case where $n=2$.
LOCATION:C204A Wells Hall
DTSTART:20230221T200000Z
DTEND:20230221T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31591
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31576@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Integration of Traditional and Telematics Data for Efficient Insurance Claims Predictions
DESCRIPTION:Speaker\: Himchan Jeong, Department of Statistics and Actuarial Science at Simon Fraser University in Canada\r\nWhile driver telematics has gained attention for risk classification in auto\r\ninsurance, scarcity of observations with telematics features has been problematic, which\r\ncould be owing to either privacy concern or adverse selection compared to the data points\r\nwith traditional features. To handle this issue, we propose a data integration technique based\r\non calibration weights. It is shown that the proposed technique can efficiently integrate the\r\nso-called traditional data and telematics data and also cope with possible adverse selection\r\nissues on the availability of telematics data. Our findings are supported by a simulation study\r\nand empirical analysis on a synthetic telematics dataset.
LOCATION:C304 Wells Hall
DTSTART:20230221T210000Z
DTEND:20230221T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31576
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31590@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Cancelled: Profinite groups and infinite Galois theory
DESCRIPTION:Speaker\: Igor Rapinchuk, MSU\r\n
LOCATION:C304 Wells Hall
DTSTART:20230222T200000Z
DTEND:20230222T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31590
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31587@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Polynomials and DP-coloring of Graphs
DESCRIPTION:Speaker\: Hemanshu Kaul, Illinois Institute of Technology\r\nDP-coloring (also called correspondence coloring) of graphs is a generalization of list coloring of graphs that has been widely studied in recent years after its introduction by Dvorak and Postle in 2015. Intuitively, DP-coloring is a variation on list coloring where each vertex in the graph still gets a list of colors, but identification of which colors are different can change from edge to edge. DP-coloring has been investigated from both the extremal (DP-chromatic number) and the enumerative (DP-color function) perspectives.\r\n \r\n\r\nIn this talk, we will give an overview of questions arising with regard to when the DP-color function equals the chromatic polynomial (or any polynomial), and how the polynomial method, through the Combinatorial Nullstellensatz and the Alon-Furedi theorem for the number of non-zeros of a polynomial, can be applied to both extremal and enumerative problems in DP-coloring. Many open problems and conjectures will be presented.
LOCATION:Online (virtual meeting)
DTSTART:20230222T200000Z
DTEND:20230222T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31587
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31588@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Conformal removability of SLE_4
DESCRIPTION:Speaker\: Konstantinos Kavvadias , University of Cambridge\r\nWe consider the Schramm-Loewner evolution (SLE_kappa) with kappa=4, the critical value of kappa>0 at or below which SLE_kappa is a simple curve and above which it is self-intersecting. We show that the range of an SLE_4 curve is a.s. conformally removable, answering a question posed by Sheffield. In order to establish this result, we give a new sufficient condition for a set X in the complex plane to be conformally removable which applies in the case that X is not necessarily the boundary of a simply connected domain. This is based on a recent joint work with Jason Miller and Lukas Schoug.
LOCATION:Online (virtual meeting)
DTSTART:20230222T200000Z
DTEND:20230222T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31588
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32599@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Property(Pr) and completed tensor product
DESCRIPTION:Speaker\: Pavel Coupek, MSU\r\n
LOCATION:C204A Wells Hall
DTSTART:20230223T191000Z
DTEND:20230223T201000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32599
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31570@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - Learning Individualized Treatment Rules with Many Treatments
DESCRIPTION:Speaker\: Yufeng Liu, University of North Carolina at Chapel Hill\r\nLearning an optimal Individualized Treatment Rule (ITR) is a very important problem in precision medicine. In this talk, we consider the challenge when the number of treatment arms is large, and some groups of treatments in the large treatment space may work similarly for the patients. Motivated by the recent development of supervised clustering, we propose a novel adaptive fusion-based method to cluster the treatments with similar treatment effects together and estimate the optimal ITR simultaneously through a single convex optimization. We establish the theoretical guarantee of recovering the underlying true clustering structure of the treatments for our method. Finally, the superior performance of our method will be demonstrated via both simulations and a real data application on cancer treatment.\r\n\r\nThis is joint work with Haixu Ma and Donglin Zeng at UNC-Chapel Hill.\r\n
LOCATION:C304 Wells Hall
DTSTART:20230223T193000Z
DTEND:20230223T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31570
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31577@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Periodic data and smooth rigidity for hyperbolic automorphisms on torus
DESCRIPTION:Speaker\: Zhenqi Wang, Michigan State University\r\nWe study the regularity of the conjugacy between an irreducible Anosov automorphism $A$\r\non torus and its small perturbation $f$.\r\nWe say that $f$ and $A$ has the same periodic data if the\r\nderivatives of the return maps of $f$ and $A$ at the corresponding periodic points are\r\nconjugate. We demonstrate that if $f$ is a $C^s$ diffeomorphism with $s$ sufficiently large and has the same periodic data as $A$, then the conjugacy is $C^{s-\epsilon}$. This completes the characterization of the most elementary $C^1$-invariant for local smooth rigidity.\r\nWe also give the first example of cocycle rigidity over fibers with conjugate periodic data.
LOCATION:A126 Wells Hall
DTSTART:20230223T200000Z
DTEND:20230223T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31577
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-30460@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Rationality in families
DESCRIPTION:Speaker\: Brendan Hassett, Brown University\r\nA smooth complex projective variety is rational if it can be obtained from projective space by algebraic surgeries, i.e. blowups and blowdowns. It is stably rational if it becomes rational after takinga product with some projective space. \r\n\r\nConsider a family of such varieties over a connected base. Which members are rational? Stably rational? We focus on recent general results and also outstanding questions that remain. These are illustrated in several key examples, including hypersurfaces of low \r\ndegree. \r\n\r\nJoint work with Kresch, Pirutka, and Tschinkel.
LOCATION:Online (virtual meeting)
DTSTART:20230223T211000Z
DTEND:20230223T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=30460
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29395@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:New approaches in simulation of transition paths
DESCRIPTION:Speaker\: Yuehaw Khoo, U Chicago\r\nTensor method can be used for compressing high-dimensional functions arising from partial differential equations (PDE). In this talk, we focus on using these methods for the simulation of transition processes between metastable states in chemistry applications, for example in molecular dynamics. To this end, we also propose a novel generative modeling procedure using tensor-network without the use of any optimization.
LOCATION:C304 Wells Hall
DTSTART:20230224T210000Z
DTEND:20230224T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29395
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31589@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Building Racial Justice in Mathematics Education: A Seat at the Breakfast Table
DESCRIPTION:Speaker\: Nicole Louie, University of Wisconsin-Madison, Chundou, University of Wisconsin-Madison\r\nEveryone seems to be talking about racial equity and justice these days. Increasingly, scholars in mathematics education are recognizing the need to center the voices of those most affected—i.e., Black, Latine, Asian, and Indigenous children and families—in these discussions. Our current project explores participatory design research (PDR) as a tool for building school, university, student, and parent capacity for centering children of color and their families as researchers and designers of middle school mathematics learning, in a small but diverse Midwestern city. In this talk, we will discuss the challenges we are experiencing and what we are learning about PDR, racial justice, and ourselves, as we work to bring youth of color to the table with us to eat, learn, and act together. Join Zoom Meeting:\r\nhttps://msu.zoom.us/j/94209936218 Passcode: PRIME
LOCATION:Online (virtual meeting)
DTSTART:20230227T190000Z
DTEND:20230227T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31589
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32603@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Capacity Constrained Barycenter Problem and its Duality
DESCRIPTION:Speaker\: Chamila Malagoda Gamage, MSU\r\nThe problem of finding a barycenter in the Wasserstein space is a nonlinear interpolation between several probability measures. In this talk we will discuss the notion of barycenters in the Wasserstein space under a capacity constraint on the mass transported and its dual formulation.\r\n$\\$\r\nThis will be a hybrid seminar and take place in C329 Wells Hall and via Zoom at https://msu.zoom.us/j/99426648081?pwd=ZEljM3BPUXg2MjVUMVM5TnlzK2NQZz09 .
LOCATION:C329 Wells Hall
DTSTART:20230227T190000Z
DTEND:20230227T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32603
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31532@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Stabilizer reduction for derived stacks
DESCRIPTION:Speaker\: Michail Savvas, University of Texas\r\nSuppose that a group acts on a variety. When can the variety and the action be resolved so that all stabilizers are finite? Kirwan gave an answer to this question in the 1980s through an explicit blowup algorithm for smooth varieties with group actions in the context of Geometric Invariant Theory (GIT). In this talk, we will explain how to generalize Kirwan's algorithm to Artin stacks in derived algebraic geometry, which, in particular, include classical, potentially singular, quotient stacks that arise from group actions in GIT. Based on joint work with Jeroen Hekking and David Rydh.
LOCATION:C304 Wells Hall
DTSTART:20230227T200000Z
DTEND:20230227T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31532
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32607@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:The quantum trace for skein algebras of surfaces (continued)
DESCRIPTION:Speaker\: Francis Bonahon, MSU\r\n I will discuss the technical details of the construction of the quantum trace homomorphism, going from the SL_2-skein algebra to the quantum Teichmüller space of Chekhov-Fock.
LOCATION:C204A Wells Hall
DTSTART:20230227T210000Z
DTEND:20230227T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32607
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32605@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Combinatorics of free probability
DESCRIPTION:Speaker\: Brent Nelson, MSU\r\nThe lattice of non-crossing partitions plays an important role in the theory of free probability. In particular, it allows one to define the so-called free cumulants, which capture the same information as a non-commutative distribution. In this talk I will provide an introduction to these ideas and show how cumulants offer a characterization of free independence as well as an easy proof of the free central limit theorem.
LOCATION:C517 Wells Hall
DTSTART:20230227T210000Z
DTEND:20230227T223000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32605
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31547@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Milnor's invariants for knots and links in closed orientable 3-manifolds
DESCRIPTION:Speaker\: Ryan Stees, Indiana University \r\nEarly in his career, John Milnor defined his seminal link invariants, now called Milnor's $\overline{\mu}$-invariants. They are topological concordance invariants of links in $S^3$, and much is known about them. However, until recently, few results have extended Milnor's work to links in other closed orientable 3-manifolds, and such extensions have done so for special classes of 3-manifolds or specific types of links. In this talk, I will discuss an extension of these invariants to concordance invariants of knots and links in any closed orientable 3-manifold, discuss some theorems that justify calling them ``Milnor's invariants", and study their properties.
LOCATION:C304 Wells Hall
DTSTART:20230228T190000Z
DTEND:20230228T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31547
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31544@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Probabilistic approach to Zamolodchikov conjecture for one point conformal blocks on the torus
DESCRIPTION:Speaker\: Andrei Prokhorov, University of Michigan\r\nLiouville field theory is the model for two-dimensional quantum gravity. It was constructed rigorously using probabilistic methods by David-Kupiainen-Rhodes-Vargas in 2016. According to the conformal bootstrap conjecture n-point correlation functions can be expressed in terms of 3-point correlation functions and so-called conformal blocks. \r\n\r\nWe restrict ourselves to the case of one point correlation function of the Liouville field theory on the torus. We want to study conformal blocks. They are described using complicated asymptotic series. The probabilistic model for them was suggested by Ghosal-Remy-Sun-Sun in 2021. It allowed showing that the asymptotic series is actually converging in a small disc. \r\n\r\nLiouville field theory has central charge c associated to it. Zamolodchikov in 1984 conjectured that conformal blocks have a limit as c goes to infinity. The limit was called classical conformal blocks. We use the probabilistic formula for conformal blocks to prove Zamolodchikov conjecture and show that the asymptotic series for them is converging in a small disc.\r\n\r\nThis is joint work with Harini Desiraju and Promit Ghosal.
LOCATION:C405 Wells Hall
DTSTART:20230301T200000Z
DTEND:20230301T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31544
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32608@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Profinite groups and infinite Galois theory
DESCRIPTION:Speaker\: Igor Rapinchuk, MSU\r\n
LOCATION:C304 Wells Hall
DTSTART:20230301T200000Z
DTEND:20230301T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32608
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32592@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:The Kromatic Symmetric Function
DESCRIPTION:Speaker\: Sophie Spirkl, University of Waterloo\r\nThe chromatic symmetric function, introduced by Stanley, counts graph colourings, recording the number of vertices of each colour. I will talk about a K-theoretic analogue of the chromatic symmetric function, in which we are colouring each vertex with a set of colours (rather than a single colour), as well as some results and open questions for this new function. Joint work with Logan Crew and Oliver Pechenik.
LOCATION:Online (virtual meeting)
DTSTART:20230301T200000Z
DTEND:20230301T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32592
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31555@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Quasi-local Hamiltonians for compact initial data sets
DESCRIPTION:Speaker\: Zhongshan An, U. Mich\r\nIn general relativity, one of the most interesting ways to construct notions of energy is the method of Hamiltonian analysis. For asymptotically flat spacetimes, this approach yields the well-known ADM mass. In order to define quasi-local energy/mass for compact initial data sets, one would like to apply the Hamiltonian analysis of GR on compact spacetimes with time-like boundary. Traditionally, this has been done based on fixing the Dirichlet boundary condition of the spacetimes — one of the most well-known work along this thread is the Brown-York quasi-local mass. In this talk we will discuss in detail the relation between the study of initial boundary value problem for vacuum Einstein equations and the Hamiltonian analysis on compact spacetimes. Then we will construct a notion of quasi-local Hamiltonian (energy) based on a well-posed initial boundary value problem.
LOCATION:C304 Wells Hall
DTSTART:20230301T211000Z
DTEND:20230301T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31555
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32609@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Everywhere convergent formal series
DESCRIPTION:Speaker\: Jie Yang, MSU\r\n
LOCATION:C204A Wells Hall
DTSTART:20230302T191000Z
DTEND:20230302T201000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32609
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31571@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - The Non-asymptotics of Reinforcement Learning
DESCRIPTION:Speaker\: Yuejie Chi, Carnegie Mellon University\r\nReinforcement learning (RL) is garnering significant interest in recent years due to its success in a wide variety of modern applications. However, theoretical understandings on the non-asymptotic sample and computational efficiencies of RL algorithms remain elusive, and are in imminent need to cope with the ever-increasing problem dimensions. In this talk, we discuss our recent progress that sheds light on understanding the efficacy of popular RL algorithms in finding the optimal policy in tabular Markov decision processes.
LOCATION:C304 Wells Hall
DTSTART:20230302T193000Z
DTEND:20230302T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31571
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32606@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY: Quasi-stability for partially hyperbolic diffeomorphisms
DESCRIPTION:Speaker\: Huyi Hu, Michigan State University\r\nThe motivation of the work is to study topological properties of\r\npartially hyperbolic systems which are similar to those of uniformly hyperbolic systems. We try to obtain some properties similar to these of uniformly hyperbolic systems by ``ignoring'' the motions along the center direction.\r\n\r\nWe show that any partially hyperbolic systems are quasi-stable in the sense that for any homeomorphism $g$ $C^0$-close to $f$, there exist a continuous map $\pi$ from $M$ to itself and a family of locally defined continuous maps $\{\tau_x\}$, which send points along the center direction, such that\r\n$$\pi\circ g=\tau_{fx}\circ f\circ\pi.\r\n$$\r\n\r\n\r\nIn particular, if $f$ has $C^1$ center foliation, then we can make the motion $\tau$ along the center foliation. \r\n\r\nAs application we obtain some continuity properties for topological entropy.
LOCATION:A126 Wells Hall
DTSTART:20230302T200000Z
DTEND:20230302T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32606
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29375@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Optimal Transport in Machine Learning and Partial Differential Equations
DESCRIPTION:Speaker\: Katy Craig, UCSB\r\nOver the past ten years, optimal transport has become a fundamental tool in statistics and machine learning: the 2-Wasserstein metric provides a new notion of distance for classifying distributions and a rich geometry for interpolating between them. In parallel, optimal transport has gained mathematical significance by providing new tools for studying stability and limiting behavior of partial differential equations, through the theory of 2-Wasserstein gradient flows.\r\n\r\nIn fact, the success optimal transport in each of these contexts ultimately relies on the same fundamental property of the 2-Wasserstein metric: as originally discovered by Otto, the 2-Wasserstein metric is unique among classical optimal transport metrics in that it has a formal Riemannian structure. In my talk, I will introduce the theory of optimal transport, explain the special geometric structure of the 2-Wasserstein metric, and illustrate the essential role it plays in how optimal transport is used in both machine learning and partial differential equations.
LOCATION:C304 Wells Hall
DTSTART:20230302T211000Z
DTEND:20230302T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29375
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32604@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Journey to “Anti-deficit Narratives”
DESCRIPTION:Speaker\: Aditya "Adi" Adiredja, University of Arizona\r\nThis talk will be a combination of a meta discussion about how I developed my research program and the main contributions of some of my projects. Specifically, I will share my journey to find a research program that simultaneously engages both equity and cognitive research. I will discuss connections between my work and Funds of Knowledge, as well as other anthropology-informed work, like Ethnomathematics and studies of the mathematics of Indigenous communities. I will share how one of my current projects with Marta Civil, Project AdeLanTe, implements the principles of anti-deficit learning\r\nand teaching, while also building on principles from Funds of Knowledge and Culturally Relevant Pedagogy. In Room 252 Erickson and on Zoom: https://msu.zoom.us/j/98177166186\r\nPassword: PRIME
LOCATION:B243 Wells Hall
DTSTART:20230313T173000Z
DTEND:20230313T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32604
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-30471@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Unipotent representations and quantization
DESCRIPTION:Speaker\: Ivan Loseu, Yale University\r\nThis talk is aimed more at the general audience. \r\n\r\n\r\n\r\nA fundamental question in the representation theory of semisimple Lie groups is to classify their irreducible unitary representations. A guiding principle here is the\r\n\r\n\r\nOrbit method, first discovered by Kirillov in the 60's for nilpotent Lie groups. It states that the irreducible unitary representations should be related to coadjoint orbits, i.e., the orbits of the Lie group action in the dual of its Lie algebra.\r\n\r\n\r\nPassing from orbits to representations could be thought of as a quantization problem and it is known that in this setting this is very difficult. For semisimple Lie groups it makes sense to speak about nilpotent orbits, and one could try to study representations that should correspond to these orbits via the yet undefined Orbit method. These representations are called unipotent: they are expected to be nicer than general ones, while one hopes to reduce the study of general representations to that of unipotent ones. I will concentrate on the case of complex Lie groups. I will explain how recent advances in the study of deformation quantizations of singular symplectic varieties allow to define unipotent representations and obtain some results about them. The talk is based on the joint work with Lucas Mason-Brown and Dmytro Matvieievskyi.
LOCATION:C304 Wells Hall
DTSTART:20230313T190000Z
DTEND:20230313T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=30471
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32596@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:An Introduction to Coarse Geometry
DESCRIPTION:Speaker\: Matthew Lorentz, MSU\r\nIn analysis we tend to focus on the "small scale" structure of a space. For example, both derivatives and continuity only depend on a very small neighborhood around a point. Coarse geometry on the other hand focuses on the "large scale" structure of a space. Coarse spaces generalize metric spaces in a way that provides an appropriate framework to study large-scale geometry. Coarse geometry is used to study: higher index theory, elliptical operators, the coarse Baum-Connes conjecture and as a consiquence the Novikov conjecture.\r\nIn this talk we will discuss what a coarse structure is, both in terms of metric spaces and in full generality. Then we will look at a few examples. Next, We will introduce uniform Roe algebras and examine their relationship to coarse structures along with recent advances in solving the rigidity problem. Then, time permitting, we will look at uniform Roe modules.
LOCATION:C517 Wells Hall
DTSTART:20230313T200000Z
DTEND:20230313T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32596
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32597@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Driving open quantum systems to a subspace: stability and large deviations.
DESCRIPTION:Speaker\: Peixue Wu, University of Illinois Urbana Champaign\r\nAbstract: Preparation of entangled states via engineered open quantum systems is proven to be successful. In our work, we initiate a study of engineered open quantum systems which drive the states to a subspace. In other word, our system will be non-ergodic. We prove some stability results and large deviation phenomenon in this setting, under some symmetry condition on the Liouvillian. This is joint work with Marius Junge and Nicholas Laracuente.
LOCATION:C304 Wells Hall
DTSTART:20230314T143000Z
DTEND:20230314T153000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32597
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31573@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Naturality of Legendrian LOSS invariant under positive contact surgery and application
DESCRIPTION:Speaker\: Shunyu Wan , University of Virginia\r\nGiven a Legendrian Knot L in a contact 3 manifold, one can associate a so-called LOSS invariant to L which lives in the knot Floer homology group. We prove that the LOSS invariant is natural under the positive contact surgery. In this talk I will review some background and definition, get the idea of the proof and try to focus on the application which is about new examples of non-simple knots.
LOCATION:C304 Wells Hall
DTSTART:20230314T153000Z
DTEND:20230314T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31573
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32601@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Small Dehn surgery and SU(2)-representations
DESCRIPTION:Speaker\: John Baldwin, Boston College\r\n In their celebrated proof of the Property P Conjecture and its sequel, Kronheimer and Mrowka proved that the fundamental group of r-surgery on a nontrivial knot in the 3-sphere admits an irreducible SU(2)-representation whenever r is at most 2 in absolute value (which implies in particular that surgery on a nontrivial knot is never a homotopy 3-sphere). They asked whether the same is true for other small values of r -- in particular, for r = 3 and 4 -- noting that it's false for r = 5 since 5-surgery on the right-handed trefoil is a lens space. I'll describe recent work which answers their question in the affirmative. Our proof involves Floer homology and also the dynamics of surface homeomorphisms. All of this work is joint with Steven Sivek, and significant parts are also joint with Zhenkun Li and Fan Ye.
LOCATION:C304 Wells Hall
DTSTART:20230314T180000Z
DTEND:20230314T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32601
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32613@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Simplicial Complexes from Graphs
DESCRIPTION:Speaker\: Margaret Bayer, University of Kansas\r\nOver the last thirty years, there has been various work on simplicial complexes defined from graphs, much from a topological viewpoint. In this talk I will present recent work (with many collaborators) on the topology of two families of simplicial complexes. One is the matching complex, the complex whose faces are sets of edges that form a matching in a graph, with new results on planar graphs coming from certain tilings. The other is the cut complex, where the facets are sets of vertices whose complements induce disconnected graphs.
LOCATION:Online (virtual meeting)
DTSTART:20230315T190000Z
DTEND:20230315T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32613
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32614@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Grothendieck's Galois Theory
DESCRIPTION:Speaker\: Igor Rapinchuk, MSU\r\n
LOCATION:C304 Wells Hall
DTSTART:20230315T190000Z
DTEND:20230315T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32614
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32620@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Ongoing Efforts to Promote Students' Engagement in Defining
DESCRIPTION:Speaker\: Kristen Vroom, MSU, Saul Barbosa, MSU, Tenchita Alzaga Elizondo , Portland State University\r\nIn this talk, we will share some of our past, present, and future efforts to support students’ defining and conjecturing activity. We will engage in some of the tasks that we are currently implementing with two calculus students. We will also discuss two future directions of our work: optimizing our task design for the whole class setting to promote equitable participation and developing science-based motivational tasks that elicit informal ideas about calculus concepts.
LOCATION:115 Erickson Hall
DTSTART:20230316T160000Z
DTEND:20230316T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32620
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32618@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Everywhere convergent formal series and Riesz’s theory II
DESCRIPTION:Speaker\: Peikai Qi, MSU\r\n
LOCATION:C204A Wells Hall
DTSTART:20230316T181000Z
DTEND:20230316T191000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32618
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31579@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - A Matrix-Mimetic Tensor Algebra for Optimal Representations of Multiway Data
DESCRIPTION:Speaker\: Elizabeth Newman, Emory University\r\nBig data has revolutionized the landscape of computational mathematics and has increased the demand for new numerical linear algebra tools to handle the vast amount of data. One crucial task is to efficiently capture inherent structure in data using dimensionality reduction and feature extraction. Tensor-based approaches have gained significant traction in this setting by leveraging multilinear relationships in high-dimensional data. In this talk, we will describe a matrix-mimetic tensor algebra that offers provably optimal compressed representations of multiway data via a family of tensor singular value decompositions (SVDs). Moreover, using the inherited linear algebra properties of this framework, we will prove that these tensor SVDs outperform the equivalent matrix SVD and two closely related tensor decompositions, the Higher-Order SVD and Tensor-Train SVD, in terms of approximation accuracy. Throughout the talk, we will provide numerical examples to support the theory and demonstrate practical efficacy of constructing optimal tensor representations.\r\n\r\nThis presentation will serve as an overview of our PNAS paper "Tensor-tensor algebra for optimal representation and compression of multiway data" (https://www.pnas.org/doi/10.1073/pnas.2015851118).
LOCATION:C304 Wells Hall
DTSTART:20230316T183000Z
DTEND:20230316T193000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31579
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32615@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:A countable partition for singular flows
DESCRIPTION:Speaker\: Fan Yang, MSU\r\nIn this talk we consider the entropy theory for singular vector fields with all singularities hyperbolic and non-degenerate. We will construct a countable partition with the property that the metric entropy for any ergodic invariant measure is finite. For singular star flows, we will show that this partition is generating. This is a joint work with Yi Shi and Jiagang Yang.
LOCATION:A126 Wells Hall
DTSTART:20230316T190000Z
DTEND:20230316T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32615
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29404@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Knot detection in Floer homology
DESCRIPTION:Speaker\: John Baldwin, Boston College\r\nA fundamental question for any knot invariant asks which knots it detects (if any). For example, it is famously open whether the Jones polynomial detects the unknot. I'll focus in this talk on the detection question for knot invariants coming from Floer theory and the Khovanov--Rozansky link homology theories. I'll survey the progress made on this question over the past twenty years, and will gesture at some of the topological ideas that go into my recent work with Sivek. I'll end with applications of our results to problems in Dehn surgery, explaining in particular how we use them to extend some of Gabai's work from the eighties.
LOCATION:C304 Wells Hall
DTSTART:20230316T201000Z
DTEND:20230316T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29404
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32610@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Regulatory Perspective on Artificial Intelligence Integrated Drug Development
DESCRIPTION:Speaker\: Menglun Wang, Food and Drug Administration\r\nThe application of Artificial Intelligence/Machine Learning (AI/ML) in drug development is expanding rapidly. AI/ML have the potential to improve the efficiency of drug development and advance precision medicine. However, there are unique challenges. The presentation will mainly focus on the topic of AI/ML applications in clinical trials, including the following parts:\r\n\r\n1. The increasing numbers of submissions over years.\r\n2. Hot therapeutic areas of AI/ML submissions.\r\n3. Types of analysis and objectives in AI/ML in submissions.\r\n4. Case examples.\r\n5. Challenges and outlooks.\r\n\r\nIn the end of the presentation, opportunities of FDA-ORISE fellowship will be introduced to senior PhD students.\r\n
LOCATION:C304 Wells Hall
DTSTART:20230317T190000Z
DTEND:20230317T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32610
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31533@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:An Overview of High-Order Finite Elements for Thermal Radiative Transfer
DESCRIPTION:Speaker\: Terry Haut, Lawerence Livermore National Lab\r\nIn this talk, I will give an overview of numerical methods for thermal radiative transfer (TRT), with an emphasis on the use of high-order finite elements for their solution. The TRT equations constitute a (6+1)-dimensional set of nonlinear PDEs that describe the interaction of a background material and a radiation field, and their solution is critical for modeling Inertial Confinement Fusion and astrophysics applications. Due to their stiff nature, they are typically discretized implicitly in time, and their solution often accounts for up to 90% of the runtime of multi-physics simulations. I will discuss some recently developed linear solvers, physics-informed preconditioners, and methods for preserving positivity that are used to make the solution to the TRT equations efficient and robust.
LOCATION:C304 Wells Hall
DTSTART:20230317T200000Z
DTEND:20230317T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31533
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31548@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:RTG Seminar: Fibered knots: what, why and how
DESCRIPTION:Speaker\: Siddhi Krishna, Columbia University\r\nFibered knots show up all over low-dimensional topology, as they provide a robust way to investigate interactions between phenomena of different dimensions. In this talk, I'll survey what they are, why you should care, and how to identify them. Then, as time permits, I'll also sketch a proof that positive braid knots are fibered. I will assume very little background for this talk -- all are welcome!
LOCATION:C304 Wells Hall
DTSTART:20230320T180000Z
DTEND:20230320T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31548
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32624@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:On outer Bi-Lipschitz Extensions of Linear JL-map embeddings of low-dimensional submanifolds of R^n
DESCRIPTION:Speaker\: Edem Boahen, MSU\r\nDimensionality reduction is the transformation of data from a high-dimensional space into a low-dimensional space so that the low-dimensional representation retains some meaningful properties of the original data, ideally close to its intrinsic dimension.\r\nA classical embedding result is the well-know “Johnson–Lindenstrauss”. The JL lemma shows how a $n$-set of points in $\mathbb{R}^N$ can be embedded into a smaller dimensional space. In this talk we present a result similar to the JL-embedding in the interesting case where instead of a discrete set we embed a compact $d$-dimensional submanifold $\mathcal{M}$ of $\mathbb{R}^N$ into $\mathbb{R}^m $ where $m$ depends on the volume, reach and dimension of $\mathcal{M}.$\r\n$\\$\r\nThis will be a hybrid seminar and take place in C329 Wells Hall and via Zoom at https://msu.zoom.us/j/99426648081?pwd=ZEljM3BPUXg2MjVUMVM5TnlzK2NQZz09 .
LOCATION:C329 Wells Hall
DTSTART:20230320T180000Z
DTEND:20230320T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32624
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31526@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Torelli theorems for certain Steiner bundles on projective space
DESCRIPTION:Speaker\: John Sheridan, Princeton University\r\nA vector bundle on projective space is called "Steiner" if it can be recognized simply as the cokernel of a map given by a matrix of linear forms. Such maps arise from various geometric setups and one can ask: from the Steiner bundle, can we recover the geometric data used to construct it? In this talk, we will mention an interesting Torelli-type result of Dolgachev and Kapranov from 1993 that serves as an origin of this story, as well as other work that this inspired. We'll then indicate our contribution which amounts to analogous Torelli-type statements for certain tautological bundles on the very ample linear series of a polarized smooth projective variety. This is joint work with R. Lazarsfeld.
LOCATION:C304 Wells Hall
DTSTART:20230320T190000Z
DTEND:20230320T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31526
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31546@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Fullness of von Neumann algebras through free Fisher information
DESCRIPTION:Speaker\: Yoonkyeong Lee, MSU\r\nIn classical probability theory, Fisher information is one of the important concepts. Voiculescu introduced the free probability analogue of this quantity, called free fisher information. In this talk, we will discuss how Free Fisher information helps us to understand a von Neumann algebra.
LOCATION:C517 Wells Hall
DTSTART:20230320T200000Z
DTEND:20230320T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31546
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32617@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Properties of the Actions and von Neumann algebras of Thompson-Like Groups from Cloning Systems
DESCRIPTION:Speaker\: Patrick DeBonis, Purdue University\r\nCloning systems are a method for generalizing Thompson's groups, for example $V_d$, that result in a family of groups, $\mathcal{T}_d(G_*)$, whose group von Neumann algebras have been intensely studied by Bashwinger and Zarmesky in recent years. We consider the group actions of a large class of $\mathcal{T}_d(G_*)$ and show they are stable, that is, $G \sim_{OE} G \times \mathbb{Z}.$ As a corollary, we answer Bashwinger and Zaremsky question about when $\mathcal{T}_d(G_*)$ is a McDuff Group in the sense of Deprez and Vaes. As a contrasting result, we show $L(V_d)$ is a prime II$_1$ factor. This is joint work with Rolando de Santiago and Krishnendu Khan.
LOCATION:C304 Wells Hall
DTSTART:20230321T143000Z
DTEND:20230321T152000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32617
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31549@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Twist positivity, L-space knots, and concordance
DESCRIPTION:Speaker\: Siddhi Krishna, Columbia University\r\nIn this talk, I’ll describe a braid word theoretic property, called “twist positivity”, which often puts strong restrictions on quantitative and geometric properties of a braid. I’ll describe some old and new results about twist positivity, as well as some new applications towards knot concordance. In particular, I’ll describe how using a suite of numerical knot invariants (including the braid index) in tandem allows one to prove that there is an infinite family of L-space knots (containing all positive torus knots and also an infinite family of hyperbolic knots) where every knot represents a distinct smooth concordance class. This confirms a prediction of the slice-ribbon conjecture. Everything I’ll discuss is joint work with Hugh Morton. I will assume little background about knot invariants for this talk – all are welcome!
LOCATION:C304 Wells Hall
DTSTART:20230321T153000Z
DTEND:20230321T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31549
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31538@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:A comparison between $SL_n$ spider categories.
DESCRIPTION:Speaker\: Anup Poudel, Ohio State\r\nIn this talk, we will explore and make comparisons between various models that exist for spherical tensor categories associated to the category of representations of the quantum group $U_q(sl_n).$ In particular, we will discuss the combinatorial model of Murakami-Ohtsuki-Yamada (MOY), the n-valent ribbon model of Sikora and the trivalent spider category of Cautis-Kamnitzer-Morrison (CKM). We conclude by showing that the full subcategory of the spider category from CKM, whose objects are monoidally generated by the standard representation and its dual, is equivalent as a spherical braided category to Sikora's quotient category. This proves a conjecture of Le and Sikora and also answers a question from Morrison's Ph.D. thesis.
LOCATION:C304 Wells Hall
DTSTART:20230321T180000Z
DTEND:20230321T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31538
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32623@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Covering spaces
DESCRIPTION:Speaker\: Marc Gotliboym, MSU\r\n
LOCATION:C304 Wells Hall
DTSTART:20230322T190000Z
DTEND:20230322T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32623
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32619@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Log-concavity, cross product conjectures, and FKG inequalities in order theory
DESCRIPTION:Speaker\: Swee Hong Chan, University of California, Los Angeles\r\nGiven a finite poset that is not completely ordered, is it always possible to find two elements x and y, such that the probability that x is less than y in the random linear extension of the poset, is bounded away from 0 and 1? Kahn-Saks gave an affirmative answer and showed that this probability falls between 3/11 (0.273) and 8/11 (0.727). The currently best known bound is 0.276 and 0.724 by Brightwell-Felsner-Trotter, and it is believed that the optimal bound should be 1/3 and 2/3, also known as the 1/3-2/3 Conjecture. Most notably, log-concave and cross product inequalities played the central role in deriving both bounds. In this talk we will discuss various generalizations of these results together with related open problems. This talk is joint work with Igor Pak and Greta Panova, and is intended for the general audience.
LOCATION:Online (virtual meeting)
DTSTART:20230322T190000Z
DTEND:20230322T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32619
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-30461@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Wave propagation on rotating cosmic string spacetimes
DESCRIPTION:Speaker\: Katrina Morgan, Northwestern University\r\nA rotating cosmic string spacetime has a singularity along a timelike curve corresponding to a one-dimensional source of angular momentum. Such spacetimes are not globally hyperbolic: they admit closed timelike curves near the so-called "string". This presents challenges to studying the existence of solutions to the wave equation via conventional energy methods. In this work, we show that forward solutions to the wave equation (in an appropriate microlocal sense) do exist. Our techniques involve proving a statement on propagation of singularities and using the resulting estimates to show existence of solutions. This is joint work with Jared Wunsch.
LOCATION:C304 Wells Hall
DTSTART:20230322T201000Z
DTEND:20230322T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=30461
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32625@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Rigid analytic geometry
DESCRIPTION:Speaker\: Patel Coupek, MSU\r\n
LOCATION:C204A Wells Hall
DTSTART:20230323T180000Z
DTEND:20230323T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32625
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31580@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - The HRT Conjecture: A call for a numerical approach
DESCRIPTION:Speaker\: Kasso Okoudjou , Tufts University\r\nThe two-scale relation in wavelet analysis dictates that a square-integrable function can be written as a linear combination of scaled and shifted copies of itself. This fact is equivalent to the existence of square-integrable functions whose time-scale shifts are linearly dependent. By contrast, by replacing the scaling operator with a modulation operator one would think that the linear dependency of the resulting time-frequency shifts of a square-integrable function might be easily inferred. However, more than two decades after C.~Heil, J.~Ramanatha, and P.~Topiwala conjectured that any such finite collection of time-frequency shifts of a non-zero square-integrable function on the real line is linearly independent, this problem (the HRT Conjecture) remains unresolved.\r\n \r\nThe talk will give an overview of the HRT conjecture and introduce an inductive approach to investigate it. I will highlight a few methods that have been effective in solving the conjecture in certain special cases. However, despite the origin of the HRT conjecture in Applied and Computational Harmonic Analysis, there is a lack of experimental or numerical methods to resolve it. I will present an attempt to investigate the conjecture numerically.
LOCATION:C304 Wells Hall
DTSTART:20230323T183000Z
DTEND:20230323T193000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31580
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32622@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Gaudin model and arc diagrams
DESCRIPTION:Speaker\: Leonid Rybnikov, HSE and Harvard University\r\nWe define a natural, purely geometrical bijection between the set solutions of Bethe ansatz equations for the Gaudin magnet chain and the set of arc diagrams of Frenkel-Kirillov-Varchenko. The former set is in natural bijection with monodromy-free sl_2-opers (aka projective structures) on the projective line with the prescribed type of regular singularities at prescribed real marked points (according to Feigin and Frenkel), while the latter indexes the canonical base in a tensor product of U_q(sl_2)-modules (via the Schechtman-Varchenko isomorphism). Both sets carry a natural action of the cactus group, i.e., the fundamental group of the real Deligne-Mumford space of stable rational curves with marked points (by monodromy of solutions to Bethe ansatz equations on the former and by crystal commuters on the latter). We prove that our bijection is compatible with this cactus group action. This is joint work with Nikita Markarian.
LOCATION:C204A Wells Hall
DTSTART:20230323T190000Z
DTEND:20230323T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32622
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29388@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Symmetry in Deep Neural Networks
DESCRIPTION:Speaker\: Robin Walters, Northeastern University\r\nDeep learning has had transformative impacts in many fields including computer vision, computational biology, and dynamics by allowing us to learn functions directly from data. However, there remain many domains in which learning is difficult due to poor model generalization or limited training data. We'll explore two applications of representation theory to neural networks which help address these issues. Firstly, consider the case in which the data represent an $G$-equivariant function. In this case, we can consider spaces of equivariant neural networks which may more easily be fit to the data using gradient descent. Secondly, we can consider symmetries of the parameter space as well. Exploiting these symmetries can lead to models with fewer free parameters, faster convergence, and more stable optimization.
LOCATION:C304 Wells Hall
DTSTART:20230323T201000Z
DTEND:20230323T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29388
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32611@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Sung-Jin Oh, UC Berkeley\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230329T201000Z
DTEND:20230329T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32611
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32626@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:An integral formula for rational homotopy groups and analytic estimates.
DESCRIPTION:Speaker\: Woongbae Park, University of Pittsburgh\r\n In this talk, I present a rational homotopy group and and its construction using minimal models given by Sullivan.\r\nAfter briefly describing Sullivan's theorem, I will consider the specific example of S^n v S^n and compute few low-dimensional rational homotopy groups.\r\nIn the second part, I introduce the Novikov integral formula for the rational homotopy group and provide analytic bound obtained from the integral formula.\r\nThe talk will end with specific examples.\r\n
LOCATION:C304 Wells Hall
DTSTART:20230330T160000Z
DTEND:20230330T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32626
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29381@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Tim Hoheisel, McGill University\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230330T201000Z
DTEND:20230330T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29381
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32594@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Dan Le, Purdue\r\n
LOCATION:C304 Wells Hall
DTSTART:20230403T190000Z
DTEND:20230403T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32594
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32598@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Real Space Quantum Optics in Localized and Periodic Media
DESCRIPTION:Speaker\: Joe Kraisler, Columbia University\r\nWe will start by introducing a real space model of a scalar electromagnetic field coupled to a continuum collection of two level atoms. From this we will obtain a pair of nonlocal partial differential equations describing the energy eigenstates that have at most one photon present in the field. The rest of the talk will discuss spectral results in two different types of atomic distributions. \r\n\r\n1. Compactly supported densities: In this setting the atoms are contained in a finite region in space. We will state necessary and sufficient conditions for the existence of eigenstates, as well as an upper bound on the number of such states.\r\n2. Periodic densities: In this setting the atoms exhibit the symmetries of a lattice. We will present a decomposition of the continuous spectrum into spectral bands and state a corresponding structure theorem.\r\n\r\nThis work is joint with Erik Hiltunen, John Schotland, and Michael Weinstein.
LOCATION:C304 Wells Hall
DTSTART:20230404T143000Z
DTEND:20230404T153000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32598
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31554@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: David Chan, Vanderbilt University\r\n
LOCATION:C304 Wells Hall
DTSTART:20230404T180000Z
DTEND:20230404T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31554
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29400@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Matt Jacobs, Purdue\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230405T201000Z
DTEND:20230405T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29400
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31581@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:Strategic Feature Extraction and Low Dimensional Representation of Games - ZOOM TALK (password the smallest prime > 100)
DESCRIPTION:Speaker\: Alexander Strang, University of Chicago\r\nGames are widely used to test reinforcement learning paradigms, to study competitive systems in economics and biology, and to model decision tasks. Empirical game theory studies games through observation of populations of interacting agents. We introduce a generic low-dimensional embedding scheme that maps agents into a latent space which enables visualization, interpolation, and strategic feature extraction. The embedding can be used for feature extraction since it represents a generic game as a combination of simpler low dimensional games. Through examples, we illustrate that these components may correspond to basic strategic trade-offs. We then show that the embedding scheme can represent all games with bounded payout, or whose payout has finite variance when two agents are sampled at random. We develop a formal approximation theory for the representation, study the stability of the embedding, provide sufficient sampling guidelines, and suggest regularizers which promote independence in the identified features.
LOCATION:C304 Wells Hall
DTSTART:20230406T183000Z
DTEND:20230406T193000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31581
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29382@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Michael Brannan, University of Waterloo\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230406T201000Z
DTEND:20230406T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29382
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31543@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:RTG Seminar: TBA
DESCRIPTION:Speaker\: Sam Gunningham, Montana State\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230410T180000Z
DTEND:20230410T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31543
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32616@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Eric Roon, University of Arizona\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230411T143000Z
DTEND:20230411T153000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32616
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31542@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Sam Gunningham, Montana State\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230411T180000Z
DTEND:20230411T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31542
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29385@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:A localized picture of the maximal development for shock forming solutions of the 3D compressible Euler equations
DESCRIPTION:Speaker\: Leonardo Abbrescia, Vanderbilt University\r\nUnderstanding the behavior of solutions to the compressible Euler equations for large times necessitates a sharp analysis of possible singularities that can form. Our understanding of shock singularities in three space dimensions has enjoyed a dramatic surge in progress in the past two decades due in part to the mathematical techniques that were developed to study Einstein’s equations. In this talk, I will discuss my recent work which provides a sharp localized description of a shock singularity as part of the boundary of maximal development of smooth data. The set of Cartesian spacetime points on which a singularity occurs, which we call the singular boundary $\mathcal{B}$, has the structure of an embedded hypersurface with very degenerate causal properties. I will give an overview of the difficulties that occur in the construction of the singular boundary, and if time permits, also discuss the construction of the Cauchy horizon which emanates from the past boundary of $\mathcal{B}$.
LOCATION:C304 Wells Hall
DTSTART:20230412T201000Z
DTEND:20230412T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29385
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31582@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - TBA
DESCRIPTION:Speaker\: Marina Meila , University of Washington\r\n
LOCATION:C304 Wells Hall
DTSTART:20230413T183000Z
DTEND:20230413T193000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31582
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-30453@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: David Fisher, Indiana University Bloomington\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230413T201000Z
DTEND:20230413T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=30453
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32595@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Shiwen Zhang, University of Massachusetts Lowell\r\n
LOCATION:C304 Wells Hall
DTSTART:20230417T143000Z
DTEND:20230417T153000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32595
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31545@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Olivier Martin, Stony Brook University\r\n
LOCATION:C304 Wells Hall
DTSTART:20230417T190000Z
DTEND:20230417T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31545
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32612@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Pierre-Louis Blayac, University of Michigan\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230418T180000Z
DTEND:20230418T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32612
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-32593@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Olga Turanova , MSU\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230419T201000Z
DTEND:20230419T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=32593
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29405@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Robert Pollack, Boston University\r\n
LOCATION:C304 Wells Hall
DTSTART:20230420T201000Z
DTEND:20230420T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29405
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31505@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA (note unusual day)
DESCRIPTION:Speaker\: Jaclyn Lang, Temple\r\n
LOCATION:C304 Wells Hall
DTSTART:20230421T190000Z
DTEND:20230421T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31505
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31534@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:High-order variational Lagrangian schemes for compressible fluids
DESCRIPTION:Speaker\: Guosheng Fu, University of Notre Dame\r\nWe present a class of high-order variational Lagrangian schemes for compressible fluids using the tool of energetic variational approach (EnVarA). This is the first time that the EnVarA framework has been applied to non isothermal models where temperature effects are non-negligible. We illustrate the main idea using the classical ideal gas model, and construct variational Lagrangian schemes that are conservative and entropy stable using EnVarA. Efficient implicit time stepping is designed so that the time step size is not restricted by the sound speed and the model is robust in the low Mach number case. Ample numerical examples will be presented to show the good performance of the proposed schemes for problems including strong shocks, low Mach number flows and multimaterial flows. This is a joint work with Prof. Chun Liu from IIT.
LOCATION:C304 Wells Hall
DTSTART:20230421T200000Z
DTEND:20230421T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31534
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31537@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:RTG Seminar: TBA
DESCRIPTION:Speaker\: Sarah Petersen, University of Colorado, Boulder\r\n
LOCATION:C304 Wells Hall
DTSTART:20230424T180000Z
DTEND:20230424T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31537
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-29398@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Ján Mináč, University of Western Ontario\r\n
LOCATION:Online (virtual meeting)
DTSTART:20230424T190000Z
DTEND:20230424T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=29398
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31575@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Alex Bols, Caltech\r\n
LOCATION:C304 Wells Hall
DTSTART:20230425T143000Z
DTEND:20230425T153000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31575
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31536@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Sarah Petersen, University of Colorado, Boulder\r\n
LOCATION:C304 Wells Hall
DTSTART:20230425T180000Z
DTEND:20230425T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31536
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-30452@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Yakov Shlapentokh-Rothman, University of Toronto\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230426T201000Z
DTEND:20230426T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=30452
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31541@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Yulong Xing, Ohio State University\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20230428T200000Z
DTEND:20230428T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31541
END:VEVENT
BEGIN:VEVENT
UID:20230322T101959-31583@math.msu.edu
DTSTAMP:20230322T101959Z
SUMMARY:ZOOM TALK (password the smallest prime > 100) - TBA
DESCRIPTION:Speaker\: Petros Drineas, Purdue University\r\n
LOCATION:C304 Wells Hall
DTSTART:20230504T183000Z
DTEND:20230504T193000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=31583
END:VEVENT
END:VCALENDAR