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DTSTART:20070311T020000
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BEGIN:VEVENT
DTSTAMP:20231113T200317
DTSTART;TZID=America/Detroit:20231121T143000
DTEND;TZID=America/Detroit:20231121T154500
SUMMARY:Workshop / Seminar:RTG Number Theory: Theta correspondence\, Hecke algebra and Springer correspondence
DESCRIPTION:Abstract: In this talk\, we consider the finite field theta correspondence between principle series. Joint with Jiajun Ma and Congling Qiu\, we explicitly describe this correspondence by analyzing the relevant Hecke algebra bimodules and applying a deformation argument. Joint with Jiajun Ma and Congling Qiu\, Zhiwei Yun\, we geometrized the whole picture. Consequently\, we obtained a relation between the Springer correspondence and theta correspondence.
UID:112627-21829202@events.umich.edu
URL:https://events.umich.edu/event/112627
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231120T100615
DTSTART;TZID=America/Detroit:20231121T160000
DTEND;TZID=America/Detroit:20231121T170000
SUMMARY:Workshop / Seminar:Differential Equations Seminar: Stable big bang singularity formation in general relativity
DESCRIPTION:Since the 1920's\, it has been known that the spatially homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetimes generically develop curvature singularities in the contracting time direction along spacelike hypersurfaces\, known as big bang singularities\, both in vacuum and for a wide range of matter models. For many years\, it remained unclear if the big bang singularities were physically relevant. It was thought by some that big bang singularities were due to the unphysical assumption of spatial homogeneity and that they would disappear in non-homogenous spacetimes\, or in other words\, big bang singularities were unstable under nonlinear perturbations as solutions to the Einstein field equations. A partial resolution to this situation came in 1967 when Hawking established his singularity theorem that guarantees a cosmological spacetime will be geodesically incomplete for a large class of matter models and initial data sets\, including highly anisotropic ones. While Hawking's singularity theorem guarantees that cosmological spacetimes are geodesically incomplete (i.e. at least one observer will experience something pathological at a finite time in the past) for a large class of initial data sets\, it is silent on the cause of the geodesic incompleteness. It has been widely anticipated that the geodesics incompleteness is due to the formation of curvature singularities\, and it is an outstanding problem in mathematical cosmology to rigorously establish the conditions under which this expectation is true and to understand the dynamical behaviour of cosmological solutions near singularities.\n\nIn this talk\, I will begin by introducing the FLRW and Kasner solutions of the Einstein-scalar field equations\, which are exact\, spatially homogeneous solutions that play a distinguished role in the analysis of big bang singularities. After briefly providing context for the FLRW and Kasner solutions in the historical development of the field of cosmology\,\nI will define what it means for a FLRW/Kasner big bang singularity to be stable. With this notion in hand\, I will then discuss the recent influential FLRW and Kasner big bang stability proofs of Rodnianski-Speck and Fournodavlos-Rodnianski-Speck. One aspect of these stability results that I will pay particular attention to is their global nature. To conclude the talk\, I will discuss some recent work done in collaboration with Florian Beyer where we improve the Rodnianski-Speck FLRW big bang stability result by establishing that the FRLW big bang is locally stable\, which is a significantly stronger notion of stability with important physical consequences that I will briefly discuss. Time permitting\, I will also briefly discuss more recent work with Florian Beyer on the stability of big bang singularities when relativistic fluids are present.
UID:114308-21832644@events.umich.edu
URL:https://events.umich.edu/event/114308
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231126T164131
DTSTART;TZID=America/Detroit:20231127T160000
DTEND;TZID=America/Detroit:20231127T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: Vandermonde matrix\, Cauchy matrix\, and Cauchy identity
DESCRIPTION:We first present a combinatorial bijective proof of the Vandermonde determinant. Then\, we present a combinatorial bijective proof of the Cauchy determinant. Finally\, we show that the Cauchy identity is an easy corollary of the Cauchy determinant.
UID:115477-21834877@events.umich.edu
URL:https://events.umich.edu/event/115477
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231126T152925
DTSTART;TZID=America/Detroit:20231127T161500
DTEND;TZID=America/Detroit:20231127T173000
SUMMARY:Workshop / Seminar:GLNT: Root Number Correlation Bias of Fourier Coefficients of Modular Forms
DESCRIPTION:In a recent machine learning based study\, He\, Lee\, Oliver\, and Pozdnyakov observed a striking oscillating pattern in the average value of the P-th Frobenius trace of elliptic curves of prescribed rank and conductor in an interval range. Sutherland discovered that this bias extends to Dirichlet coefficients of a much broader class of arithmetic L-functions when split by root number.\n In my talk\, I will discuss this root number correlation bias when the average is taken over all weight k modular newforms. I will point to a source of this phenomenon in this case and compute the correlation function exactly.
UID:110617-21825166@events.umich.edu
URL:https://events.umich.edu/event/110617
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231125T110932
DTSTART;TZID=America/Detroit:20231127T170000
DTEND;TZID=America/Detroit:20231127T180000
SUMMARY:Workshop / Seminar:Commutative Algebra Seminar: Singularities on limits of divisors along finite covers.
DESCRIPTION:One of the major questions over a field of mixed characteristics is\, \"Is there a divisor D such that the pair (R\, D) is BCM-regular when R is a splinter?\" Inspired by this\, we introduce compatible systems of divisors on finite covers of R\, which have data of divisors on all finite covers of the ring. With this\, we will define +-test/adjoint ideals for the system of divisors\, and discuss the behavior of the +-test ideals including the inverse of adjunction. This is a joint work with Karl Schwede.
UID:111187-21826174@events.umich.edu
URL:https://events.umich.edu/event/111187
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - EH 3096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231127T105536
DTSTART;TZID=America/Detroit:20231128T143000
DTEND;TZID=America/Detroit:20231128T154500
SUMMARY:Workshop / Seminar:RTG Number Theory: Motivic sheaves on affine flag varieties
DESCRIPTION:Abstract: In this talk I will discuss a categorification of integral generic Hecke algebras using motivic sheaves on affine flag varieties. This eliminates the dependence on the chosen cohomology theory\, such as l-adic or Betti cohomology\, in previous works. At the unramified level this amounts to a motivic version of the geometric Satake equivalence. On the other extreme\, at the Iwahori level we construct a motivic version of Gaitsgory's central functor. This is joint work with T. van den Hove and J. Scholbach.
UID:112630-21829205@events.umich.edu
URL:https://events.umich.edu/event/112630
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231113T100152
DTSTART;TZID=America/Detroit:20231128T160000
DTEND;TZID=America/Detroit:20231128T170000
SUMMARY:Lecture / Discussion:Colloquium Series Seminar: Non-abelian Hodge theory and the P=W conjecture
DESCRIPTION:Non-abelian Hodge theory relates topological and algebro-geometric objects associated to a compact Riemann surface. More precisely\, complex representations of the fundamental group are in correspondence with algebraic vector bundles\, equipped with an extra structure called a Higgs field. This yields a transcendental matching between two very different moduli spaces: the character variety (parametrizing representations of the fundamental group) and the Hitchin moduli space (parametrizing Higgs bundles). In 2010\, de Cataldo\, Hausel\, and Migliorini proposed the P=W conjecture\, which links precisely the topology of the Hitchin integrable system and the Hodge theory of the character variety. I will introduce the conjecture\, review its recent proofs\, and discuss how the geometry hidden behind the P=W phenomenon is connected to other branches of mathematics.
UID:109666-21822627@events.umich.edu
URL:https://events.umich.edu/event/109666
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231125T111647
DTSTART;TZID=America/Detroit:20231128T170000
DTEND;TZID=America/Detroit:20231128T180000
SUMMARY:Workshop / Seminar:Spin glass models and order of fluctuations
DESCRIPTION:Free energy is an important quantity in the study of spin glasses. Results for many spin models show that free energy\, as a random variable\, behaves differently in low versus high temperature regimes. In this talk\, we discuss the low temperature regime. In particular\, we will consider an upper bound argument for the order of fluctuations of free energy in the Ising SK model.
UID:115471-21834872@events.umich.edu
URL:https://events.umich.edu/event/115471
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231125T204048
DTSTART;TZID=America/Detroit:20231129T110000
DTEND;TZID=America/Detroit:20231129T120000
SUMMARY:Presentation:Rational duality groups and the Cohomology of SL_n(Z)
DESCRIPTION:Certain classes of groups\, such as the special linear groups over integers\, satisfy a (co)homological duality property that allows one to study their rational cohomology groups. I'll discuss a criterion to test when a group satisfies this duality\, and see how in the case of SLnZ this comes down to the fact that the Tits building is homotopy equivalent to a wedge of spheres.
UID:115473-21834873@events.umich.edu
URL:https://events.umich.edu/event/115473
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231126T180522
DTSTART;TZID=America/Detroit:20231129T143000
DTEND;TZID=America/Detroit:20231129T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Canonical form of a convex polytope via its dual volume
DESCRIPTION:The main goal of this talk is to introduce a method to compute the canonical form of a convex polytope by computing the volume of its polar dual polytope. We will first define the notion of a dual polytope and then compute the volume in a concrete example. Then we will give a proof that the dual volume actually gives the canonical form of the original convex polytope. Finally\, we will introduce a more efficient way to compute the dual volume when the polytope has many vertices but few sides\, via the Filliman Duality\, which roughly says the volume of the polytope can be obtained from triangulating its dual.
UID:115480-21834879@events.umich.edu
URL:https://events.umich.edu/event/115480
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231125T014738
DTSTART;TZID=America/Detroit:20231129T150000
DTEND;TZID=America/Detroit:20231129T160000
SUMMARY:Workshop / Seminar:Student CA Seminar: An Introduction to Group (Co)homology
DESCRIPTION:(Co)homology groups are important algebraic invariants associated to a group G. In this talk we will look at how to define group (co)homology algebraically and topologically\, prove the equivalence of the two definitions\, and briefly see examples where having both perspectives can help study a group various finiteness properties and duality properties of a group.
UID:113352-21830783@events.umich.edu
URL:https://events.umich.edu/event/113352
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20230925T232524
DTSTART;TZID=America/Detroit:20231129T160000
DTEND;TZID=America/Detroit:20231129T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: Exploring Ribbon Knots
DESCRIPTION:https://www.overleaf.com/read/ggwfrcssvbmq
UID:113076-21829996@events.umich.edu
URL:https://events.umich.edu/event/113076
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - 3096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231113T133227
DTSTART;TZID=America/Detroit:20231129T160000
DTEND;TZID=America/Detroit:20231129T170000
SUMMARY:Workshop / Seminar:Michigan Lectures in Algebraic Geometry: New perspectives on the topology of algebraic maps I
DESCRIPTION:Given a proper algebraic map f : X--> Y\, the decomposition theorem of Beilinson\, Bernstein\, Deligne\, and Gabber provides powerful tools to the study of its topology. This endows the cohomology of X with an extra structure\, known as the perverse filtration\, which measures the singularities of the map f. In recent years\, the decomposition theorem and the induced perverse filtration have been found to share surprising connections to other branches of mathematics\; these include non-abelian Hodge theory (the P=W conjecture)\, enumerative geometry (Donaldson-Thomas and BPS invariants)\, planar singularities (DAHA\, knot invariants)\, and hyper-Kähler geometries (Hodge modules\, motivic techniques). In this lecture series\, I will discuss some of these developments. If time permits\, open questions will be presented and discussed.
UID:115189-21834158@events.umich.edu
URL:https://events.umich.edu/event/115189
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231113T133723
DTSTART;TZID=America/Detroit:20231130T150000
DTEND;TZID=America/Detroit:20231130T160000
SUMMARY:Workshop / Seminar:Michigan Lectures in Algebraic Geometry: New perspectives of the topology of algebraic maps II
DESCRIPTION:Given a proper algebraic map f : X--> Y\, the decomposition theorem of Beilinson\, Bernstein\, Deligne\, and Gabber provides powerful tools to the study of its topology. This endows the cohomology of X with an extra structure\, known as the perverse filtration\, which measures the singularities of the map f. In recent years\, the decomposition theorem and the induced perverse filtration have been found to share surprising connections to other branches of mathematics\; these include non-abelian Hodge theory (the P=W conjecture)\, enumerative geometry (Donaldson-Thomas and BPS invariants)\, planar singularities (DAHA\, knot invariants)\, and hyper-Kähler geometries (Hodge modules\, motivic techniques). In this lecture series\, I will discuss some of these developments. If time permits\, open questions will be presented and discussed.
UID:115191-21834160@events.umich.edu
URL:https://events.umich.edu/event/115191
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231125T193256
DTSTART;TZID=America/Detroit:20231130T160000
DTEND;TZID=America/Detroit:20231130T165000
SUMMARY:Workshop / Seminar:Student Dyn/Geo/Top: Introduction to Heegaard Floer Homology
DESCRIPTION:Heegaard Floer Homology is a useful invariant for three manifolds\, and it has many variants that can be used to study four dimensional cobordism and knots in three spheres. In this talk I will first introduce Heegaard decomposition and Heegaard diagram and state some basic properties of them. Then\, I will make an analogy to the Lagrangian Floer Homology to define the ingredients of the Heegaard Floer Homology. Finally\, I will define the hat version of Heegaard Floer chain complex and homology.
UID:113367-21830823@events.umich.edu
URL:https://events.umich.edu/event/113367
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231124T094013
DTSTART;TZID=America/Detroit:20231130T160000
DTEND;TZID=America/Detroit:20231130T173000
SUMMARY:Workshop / Seminar:Ten Lectures on Schubert Polynomials. Lecture 8: Drift classes
DESCRIPTION:We show that every Schubert polynomial has a decomposition as a sum of polynomials\, each of which is given by a tableau formula. This corresponds to a decomposition of its set of bumpless pipe dreams into a disjoint union of classes we call drift classes. (The vexillary case\, studied in the last two lectures\, is the case when there is one drift class.)
UID:115468-21834869@events.umich.edu
URL:https://events.umich.edu/event/115468
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231125T212013
DTSTART;TZID=America/Detroit:20231201T120000
DTEND;TZID=America/Detroit:20231201T130000
SUMMARY:Workshop / Seminar:NTRG: Automorphic Representations
DESCRIPTION:We will be discussing Getz-Hahn's \"Introduction to Automorphic Representations.\"
UID:115476-21834876@events.umich.edu
URL:https://events.umich.edu/event/115476
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20230831T205016
DTSTART;TZID=America/Detroit:20231201T150000
DTEND;TZID=America/Detroit:20231201T160000
SUMMARY:Lecture / Discussion:AIM Seminar: Intriguing dynamics in a dense cell monolayer
DESCRIPTION:In this talk\, we consider an expansion of a dense monolayer of cells: a collective multicellular phenomenon\, where cells divide\, grow\, and maintain contacts with their neighbors. During migration\, cells display complex behavior\, adjusting both their division rate and their growth after division to the local mechanical environment. Experimental observations show that cells near the edge of the expanding monolayer are larger and move faster than cells deep inside the colony. To explain these observations and describe cell migration patterns\, we formulate a spatio-temporal theoretical model for multicellular dynamics in terms of the cell area distribution\; the model includes cell growth after division and effective pressure. Numerical simulations of the model predict both the speed of invasion and the width of the outer proliferative rim\; these predictions are in a good agreement with experimental observations. Theoretical analysis yields the equation for density of cells and reveals a novel type of propagating front with compact support. The velocity of front propagation (monolayer expansion) is obtained analytically and its dependence on all the relevant parameters is determined.
UID:111344-21826762@events.umich.edu
URL:https://events.umich.edu/event/111344
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231127T130216
DTSTART;TZID=America/Detroit:20231201T150000
DTEND;TZID=America/Detroit:20231201T160000
SUMMARY:Workshop / Seminar:Singularities of Hypersurfaces
DESCRIPTION:It is not hard to appreciate the beauty of singularities when you see their pictures. In this talk\, we will describe important invariants of isolated hypersurface singularities\, notably the mixed Hodge structure of the Milnor fiber and its corresponding spectrum\, with an application to bounding the number of ordinary double points on projective hypersurfaces of fixed dimension and degree.
UID:115523-21834951@events.umich.edu
URL:https://events.umich.edu/event/115523
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231127T000836
DTSTART;TZID=America/Detroit:20231201T160000
DTEND;TZID=America/Detroit:20231201T170000
SUMMARY:Workshop / Seminar:GEOM SEMINAR: On Measures Invariant under Horospherical Subgroups in Rank One Lie Groups
DESCRIPTION:Given a positive Laplace eigenfunction on a hyperbolic manifold\, there exists a horospherically invariant measure corresponding to it\, known as the Burger-Roblin measure. A question attributed to Babillot concerns whether every horospherically invariant measure arises from such a correspondence. In this talk\, I will survey previous works where affirmative answers to this question were found and present a new result extending it to a broad class of subgroups in rank one Lie groups. This is joint work with Or Landesberg\, Elon Lindenstrauss\, and Hee Oh.
UID:113648-21831387@events.umich.edu
URL:https://events.umich.edu/event/113648
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231113T134001
DTSTART;TZID=America/Detroit:20231201T160000
DTEND;TZID=America/Detroit:20231201T170000
SUMMARY:Workshop / Seminar:Michigan Lectures in Algebraic Geometry: New perspectives on the topology of algebraic maps III
DESCRIPTION:Given a proper algebraic map f : X--> Y\, the decomposition theorem of Beilinson\, Bernstein\, Deligne\, and Gabber provides powerful tools to the study of its topology. This endows the cohomology of X with an extra structure\, known as the perverse filtration\, which measures the singularities of the map f. In recent years\, the decomposition theorem and the induced perverse filtration have been found to share surprising connections to other branches of mathematics\; these include non-abelian Hodge theory (the P=W conjecture)\, enumerative geometry (Donaldson-Thomas and BPS invariants)\, planar singularities (DAHA\, knot invariants)\, and hyper-Kähler geometries (Hodge modules\, motivic techniques). In this lecture series\, I will discuss some of these developments. If time permits\, open questions will be presented and discussed.
UID:115192-21834161@events.umich.edu
URL:https://events.umich.edu/event/115192
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231201T182035
DTSTART;TZID=America/Detroit:20231204T160000
DTEND;TZID=America/Detroit:20231204T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: Heronian friezes
DESCRIPTION:In 2020 Sergey Fomin and Linus Setiabrata introduced an algebraic object called a Heronian frieze that is an analogue of the frieze patterns introduced and studied by Coxeter and Conway in the 1970s inspired by the Euclidean geometry of polygon triangulation. This survey talk will start with frieze patterns\, discuss classical results about integrality\, and draw connections to cluster algebra theory. We will build up to Heronian friezes\, including a discussion of the necessary geometric ingredients. We will end with an advertisement for current work on the case in which the polygon lies on a sphere.
UID:115714-21835416@events.umich.edu
URL:https://events.umich.edu/event/115714
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Graduate Students,Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231129T210354
DTSTART;TZID=America/Detroit:20231204T161500
DTEND;TZID=America/Detroit:20231204T173000
SUMMARY:Workshop / Seminar:Microlocal sheaves and affine Springer fibers
DESCRIPTION:Abstract: The resolutions of Slodowy slices \tilde S_e are symplectic varieties that contain the Springer fiber (G/B)_e as a Lagrangian subvariety. In joint work with R. Bezrukavnikov\, M. McBreen and Z. Yun\, we construct analogues of these spaces for homogeneous affine Springer fibers. We further understand the categories of microlocal sheaves in these symplectic spaces supported on the affine Springer fiber as some categories of coherent sheaves.\n\nIn this talk I will mostly focus on the case of the homogeneous element ts for s a regular semisimple element and will discuss some relations of these categories with the small quantum group providing a categorification of joint work with R.Bezrukavnikov\, P. Shan and E. Vasserot.\n\nI will then mention some recent application of this result to the Breuil-Mezard conjecture by T. Feng and B. Le Hung.
UID:110615-21825164@events.umich.edu
URL:https://events.umich.edu/event/110615
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231130T204116
DTSTART;TZID=America/Detroit:20231205T143000
DTEND;TZID=America/Detroit:20231205T154500
SUMMARY:Workshop / Seminar:RTG Number Theory: Pseudo-varieties of profinite graphs and spanning trees
DESCRIPTION:Abstract: We consider pro-C graphs for certain categories of finite graphs. After exploring some general theory\, we specalize to a particular pseudo-variety denoted by ε that arises naturally in constructing end point compactifications of connected abstract graphs. We show that any connected secondcountable pro-ε graph has a profinite analogue of spanning tree as in connected abstract graphs. The structure of pro-ε graphs and their fundamental profinite groups are shown to be analogous in certain ways to that of abstract graphs and their fundamental groups.
UID:112632-21829207@events.umich.edu
URL:https://events.umich.edu/event/112632
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231117T104613
DTSTART;TZID=America/Detroit:20231205T160000
DTEND;TZID=America/Detroit:20231205T170000
SUMMARY:Workshop / Seminar:Colloquium Seminar: Diffusion-based probabilistic flows and low distortion mappings
DESCRIPTION:A central question in the field of optimal transport studies optimization problems involving two measures on a common metric space\, a source and a target. The goal is to find a mapping from the source to the target\, in a way that minimizes distances. A remarkable fact discovered by Caffarelli is that\, in some specific cases of interest\, the optimal transport maps on a Euclidean metric space are Lipschitz. Lipschitz regularity is a desirable property because it allows for the transfer of analytic properties between measures. This perspective has proven to be widely influential\, with applications extending beyond the field of optimal transport.\n\nIn this talk\, we will further explore transport maps with low distortion. The key point which we shall highlight is that\, for low distortion mappings\, the optimality conditions mentioned above do not play a major role. Instead of minimizing distances\, we will consider a general construction of transport maps based on probabilistic flows\, and introduce a set of techniques to analyze their distortion. In particular\, we will go beyond the Euclidean setting and consider Riemannian manifolds as well as infinite-dimensional spaces.\n\nWe shall also discuss the emerging and intimate connections between our construction and recent advances in algorithms for generative modeling.
UID:114430-21832864@events.umich.edu
URL:https://events.umich.edu/event/114430
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231202T155428
DTSTART;TZID=America/Detroit:20231205T170000
DTEND;TZID=America/Detroit:20231205T180000
SUMMARY:Workshop / Seminar:Student Analysis: An Introduction to Vorticity and Incompressible Flow
DESCRIPTION:In this talk\, I will introduce the concept of vorticity and discuss its central role in the behavior of incompressible fluids\, focusing in particular on the role of the Lagrangian viewpoint. Time permitting\, we will discuss some well posedness results\, including the theorem of Beale-Kato-Majda.
UID:115720-21835423@events.umich.edu
URL:https://events.umich.edu/event/115720
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231201T020545
DTSTART;TZID=America/Detroit:20231206T160000
DTEND;TZID=America/Detroit:20231206T173000
SUMMARY:Workshop / Seminar:Algebraic geometry seminar: Syzygies of adjoint linear series on projective varieties
DESCRIPTION:Syzygies of algebraic varieties have long been a topic of intense interest among algebraists and geometers alike. Starting with the pioneering work of Mark Green on curves\, numerous attempts have been made to extend these results to higher dimensions. Ein and Lazarsfeld proved that if A is a very ample line bundle\, then K_X + mA satisfies property N_p for any m>=n+1+p. It has ever since been an open question if the same holds true for A ample and basepoint free. In recent joint work with Purnaprajna Bangere we give a positive answer to this question.
UID:109663-21822625@events.umich.edu
URL:https://events.umich.edu/event/109663
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231204T152115
DTSTART;TZID=America/Detroit:20231206T160000
DTEND;TZID=America/Detroit:20231206T172000
SUMMARY:Workshop / Seminar:RTG TopGeomDyn Seminar: Anosov representations in restriction to flows
DESCRIPTION:We introduce the notion of restricted Anosov representations\, characterized by their dominated splitting behavior over associated flows\, to encompass many non-Anosov representations with good geometric properties\, such as Minsky's primitive-stable representations. As a first application\, for a closed hyperbolic surface group\, we show that the collection of representations which are Anosov in restriction to the simple geodesics flow gives a domain of discontinuity for the mapping class group action (joint with Nicolas Tholozan). Secondly\, for a relatively hyperbolic group\, we show that a representation being both divergent and Weisman's extended geometrically finite is equivalent to being Anosov in restriction to a flow associated with the boundary extension.
UID:115727-21835437@events.umich.edu
URL:https://events.umich.edu/event/115727
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231202T111950
DTSTART;TZID=America/Detroit:20231207T160000
DTEND;TZID=America/Detroit:20231207T173000
SUMMARY:Workshop / Seminar:Ten Lectures on Schubert Polynomials: Lecture 9. Type C Schubert Polynomials
DESCRIPTION:After finishing our discussion of decomposing Type A Schubert polynomials into sums of drift polynomials\, we will introduce the algebra and geometry of Type C Schubert polynomials.
UID:115718-21835421@events.umich.edu
URL:https://events.umich.edu/event/115718
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231208T115146
DTSTART;TZID=America/Detroit:20231214T160000
DTEND;TZID=America/Detroit:20231214T173000
SUMMARY:Workshop / Seminar:Ten Lectures on Schubert Polynomials. Lecture 10: Schubert Polynomials in Types C\, B\, and D
DESCRIPTION:We'll finish the description of Schubert polynomials in type C\, including a relation to those in type A. Finally\, and very briefly\, we'll mention changes needed in types B and D.
UID:115948-21835875@events.umich.edu
URL:https://events.umich.edu/event/115948
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240111T120024
DTSTART;TZID=America/Detroit:20240112T150000
DTEND;TZID=America/Detroit:20240112T160000
SUMMARY:Lecture / Discussion:AIM Seminar: Randomized matrix decompositions for faster scientific computing
DESCRIPTION:Abstract: Traditional numerical methods based on expensive matrix factorizations struggle with the scale of modern scientific applications. For example\, kernel-based algorithms take a data set of size N\, form the kernel matrix of size N x N\, and then perform an eigendecomposition or inversion at a cost of O(N^3) operations. For data sets of size N >= 10^5\, kernel learning is too expensive\, straining the limits of personal workstations and even dedicated computing clusters. Randomized iterative methods have emerged as a faster alternative to the classical approaches. These methods combine randomized exploration with information about which matrix structures are important\, leading to significant speed gains.\n\nIn this talk\, I will review recent developments concerning two randomized algorithms. The first is \"randomized block Krylov iteration\"\, which uses an array of random Gaussian test vectors to probe a large data matrix in order to provide a randomized principal component analysis. Remarkably\, this approach works well even when the matrix of interest is not low-rank. The second algorithm is \"randomly pivoted Cholesky decomposition\"\, which iteratively samples columns from a positive semidefinite matrix using a novelty metric and reconstructs the matrix from the randomly selected columns. Ultimately\, both algorithms furnish a randomized approximation of an N x N matrix with a reduced rank k << N\, which enables fast inversion or singular value decomposition at a cost of O(N k^2) operations. The speed-up factor from N^3 to N k^2 operations can be 3 million. The newest algorithms achieve this speed-up factor while guaranteeing performance across a broad range of input matrices.\n\nContact: Shravan Veerapaneni
UID:114760-21833575@events.umich.edu
URL:https://events.umich.edu/event/114760
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240104T220053
DTSTART;TZID=America/Detroit:20240112T160000
DTEND;TZID=America/Detroit:20240112T170000
SUMMARY:Workshop / Seminar:GEOMETRY SEMINAR. Morse-ness in convex projective geometry
DESCRIPTION:The (Hilbert metric) geometry of properly convex domains generalizes real hyperbolic geometry. This generalization is far from the Riemannian notion of non-positive curvature but they have some intriguing similarities. In coarse geometry\, Morse geodesics embody “negatively curved” directions. In this talk\, I will explore Morse geodesics in a properly convex domain. I will show that Morse-ness can be characterized entirely using linear algebraic data (i.e. singular values of matrices that track the geodesic). Further\, I will discuss how this coarse geometric notion of Morse is closely related to a symmetric space notion of Morse (studied by Kapovich-Leeb-Porti) as well as the smoothness of boundary points. This is joint work with Theodore Weisman.
UID:116449-21836847@events.umich.edu
URL:https://events.umich.edu/event/116449
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231214T094900
DTSTART;TZID=America/Detroit:20240115T160000
DTEND;TZID=America/Detroit:20240115T170000
SUMMARY:Lecture / Discussion:2024 Marjorie Lee Browne Colloquium | Decoding Vision: Unraveling Photoreceptor Vitality & Degeneration through Mathematics
DESCRIPTION:This talk will provide a brief overview of my mathematical research in photoreceptor degeneration and vitality at both the cellular and molecular level as well as the interactions and feedback mechanisms within and between these levels. Mathematical modeling has been used to study diverse biological topics ranging from protein folding to cell interactions to interacting populations of humans but has only recently been used to study photoreceptor degeneration\, which occurs in age-related maculardegeneration (AMD) and retinitis pigmentosa (RP). There are many different maladies that can result in blindness but the ones that result from photoreceptor degeneration pose the biggest threat as there is no cure. Computer (in silico) experiments in this area have given researchers invaluable insights to mitigate blindness and\, in some cases\, re-directed experimental research. My mathematical models\, often developed in collaboration with experimental researchers and/or their data\, investigate experimentally observed photoreceptor death and rescue in retinal degeneration\, the complex interrelated metabolic pathways in cones\, and the impact of administered neurotrophic factors. Dynamical systems\, optimal control\, uncertainty and sensitivity analysis together with in silico experiments are used to analyze these systems of nonlinear differential equations. This work highlights the delicate balance of many aspects of the photoreceptor system including the inter-dependent and inter-connected feedback processes modulated by and affecting cone’s metabolism. My work provides a framework for future physiological investigations potentially leading to long-term targeted multi-faceted interventions and therapies.
UID:115816-21835675@events.umich.edu
URL:https://events.umich.edu/event/115816
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:AEM Featured,Mathematics
LOCATION:East Hall - 1324
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240112T150020
DTSTART;TZID=America/Detroit:20240116T160000
DTEND;TZID=America/Detroit:20240116T170000
SUMMARY:Workshop / Seminar:Colloquium Seminar: Stable or not: Robustness in imaging and scientific machine learning
DESCRIPTION:Stability is crucial in applications that require deriving solutions from some input data. Classically\, the notion of stability describes robustness under small perturbations of the input and regularization is employed to derive solutions from problems that lack this stable dependence. \n\nIn this talk\, we visit different problems and methods that lack stability in some\, probably less classical\, sense. First\, we discuss a phase retrieval problem which is not uniformly stable. This non-linear inverse problem cannot be tackled by classical regularization and we highlight possible connections between uniqueness and stability of this problem. Next\, we take a look at robustness through the lens of adversarial attacks both for image classification and image reconstruction. While it is known that successful attacks can be designed for data-driven methods\, we find that also classical regularization methods can be adversarially attacked.\n\nThe last part of the talk is devoted to operator learning and its stability with respect to discretizations. We propose a novel concept of neural operators that by-passes aliasing. These Representation equivalent Neural Operators (ReNOs) establish a unique and stable link between operators on infinite-dimensional spaces and their discrete realizations.
UID:116280-21836554@events.umich.edu
URL:https://events.umich.edu/event/116280
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:AEM Featured,Mathematics
LOCATION:East Hall - EH 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231208T125740
DTSTART;TZID=America/Detroit:20240116T160000
DTEND;TZID=America/Detroit:20240116T173000
SUMMARY:Lecture / Discussion:Functional MRI Speaker Series
DESCRIPTION:Title: Gaining Precision: Studying Individuals to Provide New Insights into Human Brain Networks and their Role in Control\n\nAbstract: Different regions of the brain interact with one another through large-scale networks. These network interactions are important to many complex processes\, including goal-directed control. In my lab\, we study large-scale network organization in humans and the principles by which it can vary -- and how these variations contribute to control functions and their breakdown. In the presentation\, I will review a sampling of recent studies from our lab investigating forms of variation in large-scale networks within and across people. I will then discuss how these variations influence our studies of control.\n\n\n\n\n*Light refreshments will be served.\n*Please take the Church St. elevator to the 4th floor.
UID:115949-21835876@events.umich.edu
URL:https://events.umich.edu/event/115949
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Biosciences,Brain,Cognitive Neuroscience,Imaging,Neuroimaging,Neuropsychology,Neuroscience,Psychology
LOCATION:East Hall - 4464
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240114T170749
DTSTART;TZID=America/Detroit:20240116T160000
DTEND;TZID=America/Detroit:20240116T173000
SUMMARY:Workshop / Seminar:GLNT: Integral period relations and congruence numbers
DESCRIPTION:This is a report of an ongoing work with K. Prasanna. Let p be a prime\; inspired by an earlier work by E. Urban and myself which treated the case of the quadratic base change for GL_2\, we formulate a conjecture (and establish part of it)\, in the case of the transfer from GSp(4) to GL(4)\,\n of a cohomological cuspidal representation \pi\, relating the integral periods of \pi and those of its transfer. The proof involves special values of adjoint automorphic L functions and their interpretation as congruence numbers. It seems it can be generalized to several other transfers. It has also consequences for the Bloch-Kato conjecture at p.
UID:117111-21838676@events.umich.edu
URL:https://events.umich.edu/event/117111
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240112T152948
DTSTART;TZID=America/Detroit:20240116T170000
DTEND;TZID=America/Detroit:20240116T180000
SUMMARY:Workshop / Seminar:Student Analysis Seminar: Planning Meeting + Snack Time!
DESCRIPTION:In this planning meeting\, we'll discuss logistics\, possible talk ideas\, and set up a schedule for speakers this semester. Students in any area of study are welcome to join\, and first-year graduate students are especially encouraged to join!\n\nAfter we finish\, we'll have Snack Time! Stop by to chat and eat some food. You are encouraged to bring some snacks to share!
UID:117084-21838619@events.umich.edu
URL:https://events.umich.edu/event/117084
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240116T185842
DTSTART;TZID=America/Detroit:20240117T110000
DTEND;TZID=America/Detroit:20240117T120000
SUMMARY:Presentation:Geometry of polynomial representations (part two)
DESCRIPTION:In this talk I will explain some deeper properties of GL-varieties: in particular\, I will explain how to construct curves\, which is both important and difficult. I will make this as self-contained as possible\, so even if you missed (or forgot) part one\, it should still make sense.
UID:117199-21838825@events.umich.edu
URL:https://events.umich.edu/event/117199
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 3254
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240116T115715
DTSTART;TZID=America/Detroit:20240117T130000
DTEND;TZID=America/Detroit:20240117T140000
SUMMARY:Meeting:Student AIM Seminar Planning Meeting
DESCRIPTION:Hope you had a wonderful winter break and welcome back to another semester. We are excited to kick off the Student AIM Seminar with our first planning meeting this Wednesday\, January 17th\, from 1-2 PM in East Hall 1372. \n\nPlease stop by to let us know about any social/professional event ideas\, research topics\, or speakers that you'd like us to facilitate for this semester. All are welcome!\n\nWe're looking forward to seeing you there!
UID:117208-21838829@events.umich.edu
URL:https://events.umich.edu/event/117208
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1372
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240110T162821
DTSTART;TZID=America/Detroit:20240117T150000
DTEND;TZID=America/Detroit:20240117T160000
SUMMARY:Workshop / Seminar:Student CA Seminar: Planning Meeting
DESCRIPTION:Do you have topic suggestions that you want someone to speak about? Do you want to volunteer to give a talk? Are you just curious about what this student commutative algebra seminar is about? Come and plan with us! Grad students (and undergrads & postdocs) interested in Commutative Algebra\, and possibly related topics like Algebraic Geometry\, Number Theory\, Combinatorics\, Representation Theory\, etc\, are especially encouraged to attend! Student CA is a friendly place to learn about interesting topics in commutative algebra\, and the talks are intended to be accessible to a broader algebra audience.
UID:116962-21838251@events.umich.edu
URL:https://events.umich.edu/event/116962
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240114T155635
DTSTART;TZID=America/Detroit:20240117T160000
DTEND;TZID=America/Detroit:20240117T172000
SUMMARY:Workshop / Seminar:RTG GeomTopDyn: Measure rigidity theorems in smooth dynamics.
DESCRIPTION:Classifying the invariant measures for a given dynamical system is a fundamental problem.\n\nIn the field of homogeneous dynamics\, several important theorems give us an essentially complete picture.Moving away from homogeneous dynamics — results are scarcer\, mainly due to some profound difficulties carrying out the techniques used in homogeneous dynamics.\n\nA recent development in Teichmuller dynamics — the celebrated magic wand theorem of Eskin–Mirzakhani\, gives one such example and actually provides a technique — the factorization method — for proving such results in certain systems.\n\nI will explain how one can implement the factorization method of Eskin–Mirzakhani in smooth dynamics\, in order to achieve measure classification of u-Gibbs states for non-integrable Anosov actions. Moreover\, I will try to explain some applications of the theorem\, including a result of Avila–Crovosier–Eskin–Potrie–Wilkinson–Zhang towards Gogolev’s conjecture on actions on the 3D torus.
UID:117110-21838675@events.umich.edu
URL:https://events.umich.edu/event/117110
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240112T140335
DTSTART;TZID=America/Detroit:20240118T160000
DTEND;TZID=America/Detroit:20240118T165000
SUMMARY:Workshop / Seminar:Student DGT - Planning Meeting
DESCRIPTION:This seminar welcomes anyone interested in hearing or speaking about topics within or adjacent to geometry\, dynamics or topology. In this first meeting\, we will plan and decide a talk schedule for this semester.
UID:117069-21838587@events.umich.edu
URL:https://events.umich.edu/event/117069
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240119T100813
DTSTART;TZID=America/Detroit:20240119T150000
DTEND;TZID=America/Detroit:20240119T160000
SUMMARY:Lecture / Discussion:AIM Seminar: The Heisenberg limit in quantum algorithms and learning
DESCRIPTION:Abstract: The Heisenberg limit is a fundamental limit imposed by the principles of quantum mechanics. It provides a lower bound of the amount of resources needed to achieve certain precision in an estimation task. Saturating the Heisenberg limit brings practical benefits to quantum algorithms and learning protocols. In this talk I will present two algorithms that saturate the Heisenberg limit in ground state energy estimation and in Hamiltonian learning respectively. No prior knowledge of quantum mechanics or quantum computing is assumed.\n\nThe seminar will also be broadcast via Zoom at the link https://umich.zoom.us/j/96021646996\n\nMeeting ID: 960 2164 6996\nPasscode: 034405\n\nContact: Shravan Veerapaneni
UID:114761-21833576@events.umich.edu
URL:https://events.umich.edu/event/114761
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:AEM Featured,Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240117T083123
DTSTART;TZID=America/Detroit:20240119T150000
DTEND;TZID=America/Detroit:20240119T160000
SUMMARY:Workshop / Seminar:Combinatorics seminar -- Formal geometry of affine Coxeter groups
DESCRIPTION:We study formal regions of infinite Coxeter arrangements\, which can be identified with biclosed subsets of the associated positive root system\, and which are conjectured to be the topes of an oriented matroid on the reflections of the Coxeter group. They organize into a partial order which extends the weak Bruhat order on the group. Recently\, we showed in joint work with David Speyer that this poset is a complete lattice when W is an affine Coxeter group\, resolving a conjecture of Matthew Dyer for these groups. Focusing on the affine symmetric group (type A tilde)\, we show that the completely join-irreducible elements of this lattice correspond to shards of its Coxeter arrangement\, as is known for finite Coxeter groups. We give a combinatorial description of the shards using cyclic non-crossing arc diagrams. We also show these objects biject with certain modules\, called real bricks\, over a type A tilde preprojective algebra\, and discuss the relationship between the extended weak order and the lattice of torsion classes for this algebra.
UID:116408-21836744@events.umich.edu
URL:https://events.umich.edu/event/116408
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240112T115020
DTSTART;TZID=America/Detroit:20240119T160000
DTEND;TZID=America/Detroit:20240119T170000
SUMMARY:Workshop / Seminar:Separable homology of graphs and the Whitehead complex
DESCRIPTION:We introduce a 1-complex associated with a finite regular cover of the rose and show that it is connected if and only if the fundamental group of the associated cover is generated by elements in a proper free factor of the free group. When the associated cover represents a characteristic subgroup of the free group\, the complex admits an action of Out(F_n) by isometries. We then explore the coarse geometry of the 1-complex\, showing that every component has infinite diameter\, and that the 1-complex associated with the rose is nonhyperbolic. As corollaries\, we obtain that the Cayley graph of the free group with the infinite generating set consisting of all primitive elements has infinite diameter and is nonhyperbolic.
UID:115269-21834347@events.umich.edu
URL:https://events.umich.edu/event/115269
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240117T223120
DTSTART;TZID=America/Detroit:20240122T151500
DTEND;TZID=America/Detroit:20240122T161500
SUMMARY:Workshop / Seminar:RTG Number Theory Seminar: Planning Meeting
DESCRIPTION:This is a planning meeting for this semester's RTG Number Theory seminar. We plan to have local speakers give 60-minute research talks followed by discussion. Speakers will be encouraged to share a problem or problems at the end of their talk that can serve as a starting point for discussions and collaborations among participants.\n\nPlease email Charlotte (charchan@umich.edu) if you would like to be on our mailing list.\n\n*** Note that this seminar now meets Mondays 3:15p-4:15p ***
UID:117286-21839118@events.umich.edu
URL:https://events.umich.edu/event/117286
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240121T155017
DTSTART;TZID=America/Detroit:20240122T160000
DTEND;TZID=America/Detroit:20240122T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: Planning Meeting
DESCRIPTION:Please join us for our planning meeting! We will discuss what topics we want to present/hear this semester. There will be a snack.
UID:117604-21839581@events.umich.edu
URL:https://events.umich.edu/event/117604
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Graduate Students,Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240121T153208
DTSTART;TZID=America/Detroit:20240122T161500
DTEND;TZID=America/Detroit:20240122T171500
SUMMARY:Workshop / Seminar:GLNT: Integer distance sets
DESCRIPTION:I'll talk about new joint work with Rachel Greenfeld and Marina Iliopoulou in which we address some classical questions concerning the size and structure of integer distance sets. Our main result is that any integer distance set in the Euclidean plane has all but a very small number of points lying on a single line or circle. From this\, we deduce a near-optimal lower bound on the diameter of any non-collinear integer distance set of size n and a strong upper bound on the size of any integer distance set in [-N\,N]^2 with no three points on a line and no four points on a circle.
UID:112181-21828568@events.umich.edu
URL:https://events.umich.edu/event/112181
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240119T145122
DTSTART;TZID=America/Detroit:20240123T130000
DTEND;TZID=America/Detroit:20240123T150000
SUMMARY:Other:Pop Up Opportunity Hub Coaching
DESCRIPTION:Pop up coaching allows you to meet with an Opportunity Hub coach in a space that is convenient to you! This semester\, the Opportunity Hub and LSA Psychology are partnering to bring you pop up coaching in the East Hall Psychology Atrium. Pop up coaching is a great opportunity to make meaningful progress toward your professional goals within a shorter period of time\; especially if you are a little pressed for time and are looking for on-the-spot support. For example\, if you have a grad school\, internship\, or job application due in a week\, drop-in coaching may be ideal. Pop up coaching is also great for students who are looking to try coaching for the first time.\n\nThis event is open to ALL students!
UID:117244-21838906@events.umich.edu
URL:https://events.umich.edu/event/117244
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Biopsychology\, Cognition\, And Neuroscience (Bcn),Career,Graduate School,Psychology
LOCATION:East Hall - Psychology Atrium (North)
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240111T115442
DTSTART;TZID=America/Detroit:20240123T160000
DTEND;TZID=America/Detroit:20240123T170000
SUMMARY:Workshop / Seminar:Colloquium Series Seminar: Perverse sheaves and representations of p-adic groups
DESCRIPTION:One of the first basic ideas we all learn is that a continuous function is determined by its values on a dense open subset. In representation theory\, this allows us to recognize a representation of a Lie group from an especially well-behaved locus--that of regular semisimple elements. But what if we want to study representations of matrix groups over finite fields? Lusztig's revolutionary idea in the 1980s was to replace the analytic notion of limit in the continuous setting by the algebro-geometric notion of intermediate extension in this discrete setting. I will explain this picture and describe a recent construction of perverse sheaves that give rise to positive-depth supercuspidal representations of p-adic groups. In the simplest nontrivial case\, this resolves a 2004 conjecture of Lusztig. This is joint work with R. Bezrukavnikov.
UID:113474-21831053@events.umich.edu
URL:https://events.umich.edu/event/113474
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240122T222524
DTSTART;TZID=America/Detroit:20240123T160000
DTEND;TZID=America/Detroit:20240123T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: It’s All A Lie
DESCRIPTION:This will be an introductory exploration of the relationships between Lie algebras\, Lie groups\, and basic representations of such.
UID:113077-21839807@events.umich.edu
URL:https://events.umich.edu/event/113077
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240120T202920
DTSTART;TZID=America/Detroit:20240123T170000
DTEND;TZID=America/Detroit:20240123T180000
SUMMARY:Workshop / Seminar:Student Analysis Seminar: Optimal Transport
DESCRIPTION:This will be a short introduction to the theory of optimal transportation. We will discuss the Monge-Kantorovich problem\, the dual problem\, and if time permits\, the Benamou-Brenier formula.
UID:117598-21839571@events.umich.edu
URL:https://events.umich.edu/event/117598
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240121T152504
DTSTART;TZID=America/Detroit:20240124T110000
DTEND;TZID=America/Detroit:20240124T120000
SUMMARY:Presentation:Homological stability for Hurwitz spaces
DESCRIPTION:Let G be a finite group and c a conjugacy class of G. Hurwitz spaces are certain spaces built out of the unordered configuration space of the plane and (G\, c). I will talk about work of Ellenberg—Venkatesh—Westerland\, where they prove that the homology of these spaces stabilize in certain cases. Time permitting\, I will also talk about how they apply this stability result to say something about a heuristic in number theory about class groups of quadratic field extensions over the field F_q(t)\, with q=p^n for p an odd prime.
UID:117239-21838861@events.umich.edu
URL:https://events.umich.edu/event/117239
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240119T132251
DTSTART;TZID=America/Detroit:20240124T143000
DTEND;TZID=America/Detroit:20240124T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Counting faces of polytopes using toric topology
DESCRIPTION:There are deep and subtle relations between the numbers of vertices\, edges\, triangles\, and higher dimensional faces of a polytope. The so-called g-theorem makes these precise by giving necessary and sufficient conditions for an integer vector to be counting the faces of a polytope. In this introductory talk\, we'll discuss Stanley's ingenious proof of the g-theorem\, which invokes the topology of algebraic varieties. This will take us into the realm of toric varieties\, where combinatorics and algebraic geometry intertwine. This bird's-eye view will not include hard algebraic geometry—interesting details will be the subjects of future meetings of the learning seminar.
UID:117490-21839379@events.umich.edu
URL:https://events.umich.edu/event/117490
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240121T093841
DTSTART;TZID=America/Detroit:20240124T150000
DTEND;TZID=America/Detroit:20240124T160000
SUMMARY:Workshop / Seminar:Student CA Seminar: p-monomials
DESCRIPTION:Let Z_(p) be the localization of the integers at some prime ideal (p). Polynomial rings or power series rings in n variables have a natural N^n-multigrading given by multidegree in each of the variables. Over a field\, the homogeneous elements under this multigrading are just monomials\, but over Z_(p) the homogeneous elements are \"p-monomials\": the product of a monomial with a power of the prime p. Surprisingly\, many of the nice computational lemmas from the monomial setting can be replicated for p-monomials. I will discuss the properties of p-monomials and show some examples of rings constructed using p-monomials.
UID:117315-21839160@events.umich.edu
URL:https://events.umich.edu/event/117315
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240119T103609
DTSTART;TZID=America/Detroit:20240124T161500
DTEND;TZID=America/Detroit:20240124T171500
SUMMARY:Lecture / Discussion:MCAIM Colloquium: On Flows and Diffusions: From the Many-Body Fokker-Planck Equation to Stochastic Interpolants
DESCRIPTION:Given a stochastic differential equation\, its corresponding Fokker-Planck equation is generically intractable to solve because its high dimensionality prohibits the application of standard numerical techniques. In this talk\, I will exploit an analogy between the Fokker-Planck equation and modern generative models from machine learning to develop an algorithm for its solution in high dimension. The method enables the computation of previously intractable quantities of interest\, such as the entropy production rate of active matter systems\, which quantifies the magnitude of nonequilibrium effects. I will then highlight how insight from the Fokker-Planck equation facilitates the development of a new class of generative models known as stochastic interpolants\, which generalize state of the art diffusion models in several key ways that can be leveraged to improve practical performance. Along the way\, I will argue that methods from machine learning offer a compelling solution for many fascinating high-dimensional mathematical problems that are currently out of reach with more traditional computational tools.\n\nTalk will be in-person and on Zoom: https://umich.zoom.us/j/98734707290
UID:116743-21837880@events.umich.edu
URL:https://events.umich.edu/event/116743
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:AEM Featured,Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240119T111847
DTSTART;TZID=America/Detroit:20240125T113000
DTEND;TZID=America/Detroit:20240125T130000
SUMMARY:Lecture / Discussion:Inquiry Based Learning (IBL) Lunch
DESCRIPTION:Come talk about teaching with IBL\, interactive\, and other active teaching methods over lunch! \n\nBring teaching anecdotes\, thoughts\, and your lunch. Snacks will be provided.
UID:117265-21839056@events.umich.edu
URL:https://events.umich.edu/event/117265
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240118T163435
DTSTART;TZID=America/Detroit:20240125T160000
DTEND;TZID=America/Detroit:20240125T173000
SUMMARY:Workshop / Seminar:1st order deformations
DESCRIPTION:TBA
UID:117410-21839269@events.umich.edu
URL:https://events.umich.edu/event/117410
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240117T140358
DTSTART;TZID=America/Detroit:20240125T160000
DTEND;TZID=America/Detroit:20240125T170000
SUMMARY:Workshop / Seminar:Commutative Algebra Seminar: Schmidt rank/strength and the singular locus
DESCRIPTION:The Schmidt rank/strength of a polynomial is an algebraic measure of its non-degeneracy. It has proven very useful for studying questions regarding polynomials of fixed degree in arbitrarily many variables: Schmidt used it to count integer solutions for systems of polynomial equations with rational coefficients\, Green and Tao used it to investigate the distribution of values of polynomials over finite fields\, and Ananyan and Hochster used it to prove Stillman's conjecture regarding projective dimension of ideals in polynomial rings. A central tool in all these applications is a close relationship between Schmidt rank/strength of a polynomial and a geometric measure of its non-degeneracy - The codimension of the singular locus of the polynomial. I will present a recent result on quantitative bounds for this relationship and discuss some related results and questions.\nJoint work with David Kazhdan and Alexander Polishchuk.
UID:117288-21839121@events.umich.edu
URL:https://events.umich.edu/event/117288
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240121T190448
DTSTART;TZID=America/Detroit:20240125T160000
DTEND;TZID=America/Detroit:20240125T165000
SUMMARY:Workshop / Seminar:Student Dyn/Geo/Top : Lightning Talks
DESCRIPTION:Speakers will give short 5-15 min talks on a topic that they're interested in or want to learn more about\, in an environment even more casual than usual
UID:117608-21839683@events.umich.edu
URL:https://events.umich.edu/event/117608
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240117T121933
DTSTART;TZID=America/Detroit:20240126T090000
DTEND;TZID=America/Detroit:20240126T100000
SUMMARY:Presentation:Psychology Methods Hour: \"Beyond the cycle: Valid and reliable measurement of ovarian hormone effects in human brain and behavioral research\"
DESCRIPTION:Despite a consistent body of research on the neuroactive effects of reproductive hormones\, and the growing attention given to menstrual cycle studies\, it is difficult to draw general conclusions about the menstrual cycle’s impact on brain and behavior. This is partially due to the lack of systematic methodology and consistent experimental design across studies\, alongside large inter- and intra-individual variability in hormonal patterns. In this Methods Hour\, we will delve into the challenges of researching the human menstrual cycle and take a closer look at hormonal suppression (i.e.\, oral contraceptives) research. Is the menstrual cycle different from other contextual factors (internal and external) that shape the human brain? Is there a correct way of measuring it? How do the biomedical and social sciences benefit from the study of reproductive hormones?
UID:116995-21838438@events.umich.edu
URL:https://events.umich.edu/event/116995
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Psychology
LOCATION:East Hall - 4464
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240122T115108
DTSTART;TZID=America/Detroit:20240126T150000
DTEND;TZID=America/Detroit:20240126T160000
SUMMARY:Lecture / Discussion:AIM Seminar: The 3-body problem and a 3-web of Cayley cubics on the 3-sphere
DESCRIPTION:Abstract: Finding general solutions to a mechanical system is often far too much to ask. Instead\, we look for more tractable\, special solutions\, such as the equilibria. If the system is symmetric with respect to a group action then we can also look for the relative equilibria\; these are solutions contained to a group orbit. Famous examples include the circular solutions of Euler and Lagrange in the 3-body problem. In this talk I will present a new formalism for finding relative equilibria by defining a 'web structure' on shape space\, and demonstrate this by classifying the relative equilibria for the spherical 3-body problem.\n\nContact: AIM Seminar Organizers
UID:114762-21833577@events.umich.edu
URL:https://events.umich.edu/event/114762
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240119T204314
DTSTART;TZID=America/Detroit:20240126T150000
DTEND;TZID=America/Detroit:20240126T160000
SUMMARY:Workshop / Seminar:Nilsequences as extremal objects in additive combinatorics
DESCRIPTION:We will begin by introducing the use of higher-order Fourier analysis in additive combinatorics for a general audience. In particular\, we will discuss the arithmetic regularity lemma and how it identifies a certain class of arithmetically-structured functions -- nilsequences -- as extremal objects for problems in additive combinatorics. We will then discuss how it has recently come to light that the analysis of nilsequences on certain arithmetic patterns -- those which satisfy a certain algebraic criterion known as the flag condition -- is easier than the general case\, and discuss some recent ideas and developments in overcoming the difficulties that arise when the arithmetic pattern of interest is not flag.
UID:116413-21836761@events.umich.edu
URL:https://events.umich.edu/event/116413
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240121T203928
DTSTART;TZID=America/Detroit:20240126T150000
DTEND;TZID=America/Detroit:20240126T160000
SUMMARY:Workshop / Seminar:The Mumford-Tate conjecture
DESCRIPTION:TBA
UID:117609-21839687@events.umich.edu
URL:https://events.umich.edu/event/117609
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240126T084648
DTSTART;TZID=America/Detroit:20240129T150000
DTEND;TZID=America/Detroit:20240129T160000
SUMMARY:Workshop / Seminar:RTG NT: On Kloosterman sums and representation theory
DESCRIPTION:Abstract: I will give a quick overview of twisted Kloosterman sums and their associated sheaves defined by Deligne--Katz. Then I will talk about matrix Kloosterman sums defined by Erdélyi--Tóth and about my recent work that reduces these to classical Kloosterman sums and Hall--Littlewood polynomials. In both parts of the talk\, I will explain a relation between exterior/symmetric powers of the Kloosterman sheaf and a special value of a Bessel function of a representation of GLn(Fq).
UID:117823-21840074@events.umich.edu
URL:https://events.umich.edu/event/117823
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240129T004258
DTSTART;TZID=America/Detroit:20240129T160000
DTEND;TZID=America/Detroit:20240129T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: Lightning talks!
DESCRIPTION:We will hear short mini talks from anywhere in combinatorics! This semester\, the theme is a 'conjecture' you've encountered. Each talk will be 5-15 minutes\, with slots available to anyone in attendance.
UID:117958-21840231@events.umich.edu
URL:https://events.umich.edu/event/117958
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240125T090327
DTSTART;TZID=America/Detroit:20240129T161500
DTEND;TZID=America/Detroit:20240129T171500
SUMMARY:Workshop / Seminar:GLNT: Spin structures on number fields and class group statistics
DESCRIPTION:Spin structures determine quadratic refinements of the linking form on the torsion part of homology for closed oriented 3 manifolds and the intersection form on mod 2 homology of closed oriented surfaces. In this talk\, I will outline a counterpart of this story for number fields and describe how it explains an anomaly in class group statistics. This is a report on joint work with Akshay Venkatesh.
UID:112524-21829078@events.umich.edu
URL:https://events.umich.edu/event/112524
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240122T121246
DTSTART;TZID=America/Detroit:20240130T160000
DTEND;TZID=America/Detroit:20240130T170000
SUMMARY:Workshop / Seminar:Colloquium Seminar: Random curves and surfaces
DESCRIPTION:How can you sample a surface uniformly at random? A natural approach is to consider a uniformly sampled planar map\, which is a model for a discrete surface studied in many branches of both math and physics. When the size of the surface goes to infinity it converges to the continuum random surface known as a Liouville quantum gravity surface\, which was originally introduced in the physics literature. We will give an introduction to these objects and present a powerful technique to study them known as conformal welding\, where the random fractal curves known as Schramm-Loewner evolutions appear.
UID:113617-21831239@events.umich.edu
URL:https://events.umich.edu/event/113617
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240128T145216
DTSTART;TZID=America/Detroit:20240130T160000
DTEND;TZID=America/Detroit:20240130T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: Inverse Semigroups\, Morita Equivalence\, and More!
DESCRIPTION:In this talk we give a brief introduction to the theory of inverse semigroups\, a generalization of a group. We then dive into some examples of inverse semigroups before introducing the notion of a local isomorphism between inverse semigroups. Finally\, we end off by discussion characterizations of Morita equivalence of certain types of inverse semigroups.
UID:117695-21839845@events.umich.edu
URL:https://events.umich.edu/event/117695
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240127T163920
DTSTART;TZID=America/Detroit:20240130T170000
DTEND;TZID=America/Detroit:20240130T180000
SUMMARY:Workshop / Seminar:Student Analysis Seminar: Linearized diocotron perturbation (characterization for l ≥ 2 eigenmode)
DESCRIPTION:The linear stability analysis of the l = 1 diocotron perturbations in a low density single charged plasma confined in a cylindrical Penning trap has been precisely discussed. It has been shown that the l = 1 case admits at most an algebraic instability (no discrete spectra). Now for l ≥ 2 cases\, we give a priori estimate for the spectra\, and present a characterization for the orders of eigenvalues as poles of the Laplace transform.\n\nShuhong will bring souvenirs for everyone\, to celebrate the upcoming Lunar New Year!
UID:117924-21840196@events.umich.edu
URL:https://events.umich.edu/event/117924
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240128T105628
DTSTART;TZID=America/Detroit:20240131T110000
DTEND;TZID=America/Detroit:20240131T120000
SUMMARY:Presentation:Strength of polynomials over finite fields and equidistribution
DESCRIPTION:Strength is an algebraic measure of nondegeneracy for multivariate polynomials. Motivated by questions in additive combinatorics\, Green and Tao proved that polynomials over finite fields with high strength have equidistributed values. This result led to a flurry of various extensions and improvements by many others. I will survey what is known both qualitatively and quantitatively and then introduce an equidistribution result for polynomials with inputs restricted to lie on a variety.\nJoint work with Tamar Ziegler.
UID:117678-21839828@events.umich.edu
URL:https://events.umich.edu/event/117678
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240128T225011
DTSTART;TZID=America/Detroit:20240131T143000
DTEND;TZID=America/Detroit:20240131T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Toric Varieties from Fans
DESCRIPTION:Arising in fields ranging from algebraic geometry to theoretical physics\, toric varieties provide a concrete link between combinatorial geometry and algebraic geometry. In this introductory talk\, we'll focus our attention on one of the fundamental types of toric varieties\, toric varieties constructed from fans.
UID:117948-21840221@events.umich.edu
URL:https://events.umich.edu/event/117948
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240126T001445
DTSTART;TZID=America/Detroit:20240131T150000
DTEND;TZID=America/Detroit:20240131T160000
SUMMARY:Workshop / Seminar:Student CA Seminar: Standard monomial theory
DESCRIPTION:The theory of standard monomials provides a combinatorial approach to studying determinantal rings via a correspondence between products of minors and Young tableaux. In this talk\, we will introduce standard monomials and their key properties\, including the straightening law. We will then show how to use these properties to study (F-)singularities of determinatal rings.
UID:117453-21839333@events.umich.edu
URL:https://events.umich.edu/event/117453
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240118T114811
DTSTART;TZID=America/Detroit:20240131T160000
DTEND;TZID=America/Detroit:20240131T172000
SUMMARY:Workshop / Seminar:Algebraic Geometry Seminar: Quartic surfaces in arbitrary characteristic
DESCRIPTION:I will review the old and recent results on quartic surfaces and three-dimensional Fano and Calabi-Yau varieties (in characteristic 2)\, which they define via the double covers of the space branched along a quartic surface. I will give special attention to quartic surfaces over an algebraically closed field of positive characteritic.
UID:117268-21839059@events.umich.edu
URL:https://events.umich.edu/event/117268
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240130T205105
DTSTART;TZID=America/Detroit:20240131T160000
DTEND;TZID=America/Detroit:20240131T173000
SUMMARY:Workshop / Seminar:Logic Seminar: A crash course in syntactic algebras and Stone-type dualities
DESCRIPTION:We will explain\, via the simple example of propositional logic\, the process by which a well-behaved logic with a classical semantics may be given a generalized algebraic semantics\, and then turned into a \"syntactic algebra\" forming the universal such semantics\, which is then (in the best cases) recoverable from the space of all classical models equipped with suitable \"dual\" structure. Time permitting\, we will briefly sketch how similar ideas can be carried over to first-order logic.
UID:118159-21840576@events.umich.edu
URL:https://events.umich.edu/event/118159
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240123T113249
DTSTART;TZID=America/Detroit:20240201T160000
DTEND;TZID=America/Detroit:20240201T170000
SUMMARY:Workshop / Seminar:Commutative Algebra Seminar: Standard monomial theory modulo Frobenius in characteristic two
DESCRIPTION:Over a field of characteristic zero\, standard monomial theory and Young tableaux provide a connection between determinantal ideals of polynomial rings and irreducible representation theory of GL_n. In this talk\, we present work towards developing an analogous theory over a field of characteristic two by working modulo a Frobenius power. As a result\, we obtain modular GL_n-representations whose characters are given by particular truncated Schur polynomials\, thus proving a conjecture by Gao-Raicu-VandeBogert in the characteristic two case. This is joint work with Laura Casabella.
UID:117452-21839332@events.umich.edu
URL:https://events.umich.edu/event/117452
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240131T114602
DTSTART;TZID=America/Detroit:20240201T160000
DTEND;TZID=America/Detroit:20240201T173000
SUMMARY:Workshop / Seminar:Higher Order Deformations
DESCRIPTION:TBA
UID:117415-21839281@events.umich.edu
URL:https://events.umich.edu/event/117415
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240127T111633
DTSTART;TZID=America/Detroit:20240201T160000
DTEND;TZID=America/Detroit:20240201T170000
SUMMARY:Workshop / Seminar:Student Dyn/Geo/Top: On the Moving Sofa Problem
DESCRIPTION:Modeling the situation of moving furniture around\, the moving sofa problem asks for the maximum area of a planar shape that can move around the corner in an L-shaped hallway of width 1. The problem was posed by Leo Moser in 1966\, and the best known lower bound of 2.2195... was proved by Gerver in 1994\, by constructing a sofa whose boundary consists of 18 special curves. While it is conjectured that Gerver's sofa attains the maximum area\, the best published upper bound of 2.37 was proved by Kallus and Romik in 2018 using computer assistance.\n\nImproving upon the computer-assisted approach of Kallus and Romik\, we improve the upper bound to 2.32. Moreover\, without any computer assistance\, we prove a conceptually new upper bound of $1 + \pi^2/8$ = 2.2337... that is much closer to the lower bound of Gerver\, on a large subset of shapes which includes Gerver's sofa. We also discuss the possibility of making the upper bound of 2.2337... unconditional by building upon the approaches of the two results.
UID:117919-21840191@events.umich.edu
URL:https://events.umich.edu/event/117919
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240122T161743
DTSTART;TZID=America/Detroit:20240202T150000
DTEND;TZID=America/Detroit:20240202T160000
SUMMARY:Lecture / Discussion:AIM Seminar: Small dispersion asymptotics of Benjamin-Ono soliton ensembles
DESCRIPTION:Abstract: The Benjamin-Ono equation is a nonlinear\, nonlocal PDE that\, roughly speaking\, is a model for waves along the interface of two fluids. We discuss some recent results on asymptotics of soliton solutions to the Benjamin-Ono equation and mention a new explicit formula of P. Gérard\, along with some implications.\n\nContact: AIM Seminar Organizers
UID:114763-21833578@events.umich.edu
URL:https://events.umich.edu/event/114763
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240128T104020
DTSTART;TZID=America/Detroit:20240202T150000
DTEND;TZID=America/Detroit:20240202T160000
SUMMARY:Workshop / Seminar:Derived categories and semiorthogonal decomposition in geometry
DESCRIPTION:In this talk\, I will review some definitions from the theory of derived categories\, especially the notion of a semiorthogonal decomposition. I will give some interesting geometric examples before trying to explain the relation between derived categories\, SODs and birational geometry.
UID:117935-21840207@events.umich.edu
URL:https://events.umich.edu/event/117935
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240126T105835
DTSTART;TZID=America/Detroit:20240202T150000
DTEND;TZID=America/Detroit:20240202T160000
SUMMARY:Workshop / Seminar:Incidences and tilings
DESCRIPTION:We show that various classical theorems of real/complex linear incidence geometry\, such as the theorems of Pappus\, Desargues\, Möbius\, and so on\, can be interpreted as special cases of a single \"master theorem\" that involves an arbitrary tiling of a closed oriented surface by quadrilateral tiles. This yields a general mechanism for producing new incidence theorems and generalizing the known ones. \n\nThis is joint work with Pavlo Pylyavskyy [arXiv:2305.07728]. The same material was presented last week at the undergraduate Math Club\, and in a Math 668 lecture in December.
UID:117838-21840092@events.umich.edu
URL:https://events.umich.edu/event/117838
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240202T134520
DTSTART;TZID=America/Detroit:20240205T150000
DTEND;TZID=America/Detroit:20240205T160000
SUMMARY:Workshop / Seminar:RTG NT: Covers of reductive groups and functoriality
DESCRIPTION:Abstract: A key player in the Langlands program is the L-group ^LG of a connected reductive group G over a local or global field. It underpins both pillars of the program: the reciprocity conjecture\, which relates automorphic representations of G to Galois representations valued in ^LG\, and the functoriality conjecture\, which relates automorphic representations of two different groups whose L-groups are related. We will discuss how considerations of functoriality lead to an extension of the concept of L-group to certain non-linear covering groups\, and how these can be organized using a new kind of fundamental group associated to G. We will focus on the case of a local field.
UID:117825-21840076@events.umich.edu
URL:https://events.umich.edu/event/117825
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240204T130442
DTSTART;TZID=America/Detroit:20240205T160000
DTEND;TZID=America/Detroit:20240205T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: Configurations\, Graphs and Trees
DESCRIPTION:Configuration Spaces give good prototypical examples to understand the (co)homology of certain groups like braid groups\, and the phenomenon of homological stability. In this talk we will explore the topology of configurations of n points on the plane. Through pictures and examples\, we will first see how the motion of the particles generates (co)homology classes of these spaces. We will then see how to associate trees and graphs to these classes\, and describe a combinatorial pairing between trees and graphs that is analogous to the pairing between cohomology and homology.
UID:118361-21840937@events.umich.edu
URL:https://events.umich.edu/event/118361
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240204T131142
DTSTART;TZID=America/Detroit:20240206T150000
DTEND;TZID=America/Detroit:20240206T160000
SUMMARY:Workshop / Seminar:Applying Variational Quantum and Quantum-Inspired Algorithms to the Linear Complementarity Problem
DESCRIPTION:Abstract: Variational quantum algorithms (VQAs) are hybrid quantum–classical algorithms that seek to harness the advantage of quantum computers while simultaneously mitigating the drawbacks of the noisy\, intermediate-scale (NISQ) quantum hardware existing today. VQAs have an established theoretical potential\, but their ability to effectively solve problems arising from practical applications\, and whether this utility can be wholly replicated by quantum-inspired classical algorithms\, remains an active area of interest. We present a novel application of both the Variational Quantum Linear Solver (VQLS) and the Variational Neural Linear Solver (VNLS)—an existing VQA for solving systems of linear equations\, and its quantum-inspired fully classical counterpart—as the key component within a larger minimum map Newton solver for a complementarity-based rigid body contact model. Using each algorithm\, we demonstrate that this solver accurately depicts the dynamics of the model system’s rigid spherical bodies as they collide. These results indicate that quantum and quantum-inspired linear algebra algorithms may provide a satisfactory alternative to standard linear algebra solvers for modeling certain physical systems.
UID:118362-21840938@events.umich.edu
URL:https://events.umich.edu/event/118362
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Electrical Engineering and Computer Science,Mathematics
LOCATION:East Hall - 1068
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240201T142759
DTSTART;TZID=America/Detroit:20240206T160000
DTEND;TZID=America/Detroit:20240206T170000
SUMMARY:Workshop / Seminar:Marton's Conjecture\, aka the Polynomial Freiman--Ruzsa conjecture
DESCRIPTION:A function f(x) is linear if f(x+y)=f(x)+f(y) for all pairs (x\,y). Suppose f is \"a bit linear\" -- say\, f(x+y)=f(x)+f(y) for 1% of pairs (x\,y). What can you say about f? Must it be closely related to an actually linear function? If so\, how closely?\n\nThis question turns out to be equivalent to asking for good quantitative bounds in the Freiman--Ruzsa theorem\, a foundational result in additive combinatorics. Marton gave a formulation\, equivalent to the statement above\, which she conjectured should have polynomial bounds. I will outline a recent proof of this conjecture.\n\nJoint work with Timothy Gowers\, Ben Green and Terence Tao.
UID:115964-21835947@events.umich.edu
URL:https://events.umich.edu/event/115964
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240206T090956
DTSTART;TZID=America/Detroit:20240206T160000
DTEND;TZID=America/Detroit:20240206T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar
DESCRIPTION:This week's seminar features two talks\, namely:\n\"Optimal Control of a Solar-Powered Racecar\" by Matthew Anderson and\n\"In-Duck-Tion\" by Martha Wolf
UID:118443-21841082@events.umich.edu
URL:https://events.umich.edu/event/118443
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240205T143837
DTSTART;TZID=America/Detroit:20240207T110000
DTEND;TZID=America/Detroit:20240207T120000
SUMMARY:Presentation:Divisibility of character values of the symmetric group
DESCRIPTION:In 2017\, Miller computed the character tables of $S_n$ for all $n$ up to $38$ and looked at various statistical properties of the entries. Characters of symmetric groups take only integer values\, and\, based on his computations\, Miller conjectured that almost all entries of the character table of $S_n$ are divisible by any fixed prime power as $n$ tends to infinity. Previously\, Sound and I proved this conjecture for any fixed prime. In this talk\, I will discuss joint work with Sound that fully resolves it\, and mention some related open problems.\n\n**Note regarding location: The Pillsbury room is located on Floor 4M on the Psychology side of East Hall. To get to the room\, you enter the Psychology side of East Hall from the Church Street entrance and before you get into the Psych atrium\, there is an elevator to your left. Take the elevator to Floor 4M and the elevator opens into the room.**
UID:118233-21840681@events.umich.edu
URL:https://events.umich.edu/event/118233
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240204T221403
DTSTART;TZID=America/Detroit:20240207T143000
DTEND;TZID=America/Detroit:20240207T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Fans from Toric Varieties
DESCRIPTION:This talk will begin building up a dictionary relating geometric properties of toric varieties to combinatorial properties of fans. In particular\, we will analyze singularities and compactness of toric varieties. As a by-product of our dictionary\, we will see how to form a fan from a normal toric variety.
UID:118368-21840943@events.umich.edu
URL:https://events.umich.edu/event/118368
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240203T160648
DTSTART;TZID=America/Detroit:20240207T150000
DTEND;TZID=America/Detroit:20240207T160000
SUMMARY:Workshop / Seminar:Student CA Seminar: Graded and local rings
DESCRIPTION:A local ring has a unique maximal ideal. A graded ring often has many maximal ideals\; however\, if it has a unique *homogeneous* maximal ideal then in practice the graded ring will behave like a local ring. We will see some examples of this phenomenon\, as well as learn about why it occurs.
UID:117316-21839163@events.umich.edu
URL:https://events.umich.edu/event/117316
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240202T130355
DTSTART;TZID=America/Detroit:20240207T150000
DTEND;TZID=America/Detroit:20240207T155000
SUMMARY:Workshop / Seminar:Student Number Theory: Additive Combinatorics\, Uniformity\, and Patterns in Primes
DESCRIPTION:Additive combinatorics provides a powerful framework for understanding additive structure in finite-rank abelian groups. I’ll give an overview of a few of the main techniques in this field\, focusing on the structure/randomness dichotomy pioneered by Szemerédi and Gowers. Along the way\, I’ll also introduce a close connection between additive combinatorics and ergodic theory\, and explain how the transference principle developed by Green and Tao allows additive combinatorics to be applied to questions of additive structure in the set of prime numbers.
UID:118297-21840849@events.umich.edu
URL:https://events.umich.edu/event/118297
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240202T183335
DTSTART;TZID=America/Detroit:20240207T160000
DTEND;TZID=America/Detroit:20240207T173000
SUMMARY:Workshop / Seminar:Algebraic Geometry Seminar: Atiyah duality and applications
DESCRIPTION:In topology\, Atiyah duality provides a geometric model for the dual of the suspension spectrum of a smooth manifold. In this talk\, we export this into algebraic geometry by proving an analogous claim in the non-A^1-invariant stable motivic homotopy theory of Annala-Hoyois-Iwasa. Besides recovering many Poincaré duality type results\, it has quite interesting consequences for the behavior of the A^1-colocalization functor R. Namely\, R is a way of turning a cohomology theory into an A^1-invariant one without changing the on smooth projective varieties. Using this observation\, we can prove the independence of logarithmic cohomology groups from the choice of good compactification\, and that certain cohomology groups are birational invariants.
UID:115610-21835110@events.umich.edu
URL:https://events.umich.edu/event/115610
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240201T212348
DTSTART;TZID=America/Detroit:20240207T160000
DTEND;TZID=America/Detroit:20240207T173000
SUMMARY:Workshop / Seminar:RTG TopGeomDyn: Introduction to Exponential Mixing Via Additive Combinatorics
DESCRIPTION:This talk will provide background on some of the concepts that will appear in the lecture on Friday. Time permitting\, we will introduce some of the key players from the theory of anisotropic Banach spaces\, inverse theory in additive combinatorics\, Fourier transforms of dynamically defined measures\, and the interactions among them. The two lectures will be independent of one another and will not assume background in these topics.
UID:115252-21834274@events.umich.edu
URL:https://events.umich.edu/event/115252
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240118T164252
DTSTART;TZID=America/Detroit:20240208T160000
DTEND;TZID=America/Detroit:20240208T173000
SUMMARY:Workshop / Seminar:Pro-representable formal moduli and examples
DESCRIPTION:TBA
UID:117416-21839273@events.umich.edu
URL:https://events.umich.edu/event/117416
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240204T202853
DTSTART;TZID=America/Detroit:20240208T160000
DTEND;TZID=America/Detroit:20240208T165000
SUMMARY:Workshop / Seminar:Student Dyn/Geo/Top: Poisson Geometry and Symplectic Groupoids
DESCRIPTION:In this talk\, we will give a basic introduction to Poisson geometry and examine the relation between Poisson manifolds and symplectic groupoids. If time permits\, we will examine how this relates to deformation quantization. Only a basic familiarity with manifolds will be assumed.
UID:118366-21840941@events.umich.edu
URL:https://events.umich.edu/event/118366
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240122T115246
DTSTART;TZID=America/Detroit:20240209T150000
DTEND;TZID=America/Detroit:20240209T160000
SUMMARY:Lecture / Discussion:AIM Seminar/Smereka Prize Lecture: Mathematical Modeling of Circadian Rhythms from Wearable Data
DESCRIPTION:Abstract: Models that capture the human circadian clock on a macroscopic level have been used effectively in predicting circadian phase\, particularly for day worker and healthy populations. Adapting and applying these models to work with wearable data from populations with disrupted circadian phases (such as shift workers\, cancer patients\, and individuals with COVID-19) has been a recent key area of research. This talk will present limit cycle oscillator models for the circadian pacemaker\, show their ability to predict human circadian phase based on real-world activity data from consumer-grade wearable devices\, and consider the effects of lighting schedules and parameters on the model outputs. We will further discuss algorithms for the analysis of oscillatory wearable data such as heart rate and body temperature\, and the application of these techniques to varying populations. Through this framework we see changes to physiologically-relevant features at different times around COVID-19 symptom onset\, enhancing our understanding of disease progression and speaking to the early detection potential. These projects aim to utilize mathematical and computational tools to generate meaningful additions to our understanding of circadian rhythms\, personal health\, and disease in the real-world.\n\nContact: S. Alben
UID:114765-21833580@events.umich.edu
URL:https://events.umich.edu/event/114765
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240204T095341
DTSTART;TZID=America/Detroit:20240209T150000
DTEND;TZID=America/Detroit:20240209T160000
SUMMARY:Workshop / Seminar:Compactifying the universal elliptic curve using toric geometry
DESCRIPTION:One can compactify the universal elliptic curve by the following strategy: the moduli is an open 1-dimensional variety\, so you can uniquely compactify it. And then the universal elliptic curve is 2-dimensional\, so you can compactify whatever you want and choose the minimal resolution. I'll try to convince you that this is bad and explain how you can do better in a systematic way.
UID:118359-21840935@events.umich.edu
URL:https://events.umich.edu/event/118359
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240123T130817
DTSTART;TZID=America/Detroit:20240209T150000
DTEND;TZID=America/Detroit:20240209T160000
SUMMARY:Workshop / Seminar:The combinatorics of minuscule posets in mirror symmetry for homogeneous spaces
DESCRIPTION:We will demonstrate the various ways minuscule posets appear in mirror symmetry statements for cominuscule homogeneous spaces in the joint work with Charles Wang (UMich). The mirror models of these spaces arise through Langlands duality\, and hence use the corresponding minuscule representations. The weight spaces of these representations can be described using minuscule posets\, so it is not surprising that the combinatorics of these posets govern the various objects appearing.
UID:116409-21836745@events.umich.edu
URL:https://events.umich.edu/event/116409
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240131T113605
DTSTART;TZID=America/Detroit:20240209T160000
DTEND;TZID=America/Detroit:20240209T170000
SUMMARY:Workshop / Seminar:GEOMETRY SEMINAR: Exponential Mixing Via Additive Combinatorics
DESCRIPTION:The Bowen-Ruelle conjecture predicts that geodesic flows on negatively curved manifolds are exponentially mixing with respect to all their equilibrium states. Dolgopyat pioneered a method rooted in the thermodynamic formalism that settled the conjecture for surfaces. Soon after\, Liverani developed an intrinsic functional analytic analog of Dolgopyat's method allowing to settle the case of Liouville measures in higher dimensions\, while simultaneously producing more information on the rates of mixing. Despite these important breakthroughs\, the conjecture remains open in general\, even in the case of measures of maximal entropy. In this talk\, we will discuss a method for extending the functional analytic approach to deal with non-smooth invariant measures in a concrete algebraic setting. The key ingredient is a reduction of the problem to one regarding Fourier transforms of dynamically defined measures which we address using new machinery in additive combinatorics. The talk will not assume prior knowledge of these topics.
UID:115248-21834267@events.umich.edu
URL:https://events.umich.edu/event/115248
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240201T091216
DTSTART;TZID=America/Detroit:20240212T150000
DTEND;TZID=America/Detroit:20240212T160000
SUMMARY:Workshop / Seminar:RTG NT: Theta correspondence and Arthur packets
DESCRIPTION:Abstract: The local theta correspondence does not preserve L-packets. As a remedy\, Adams conjectured that instead of L-packets\, the theta correspondence preserves Arthur packets. Moeglin verified Adams' conjecture when the theta correspondence has sufficiently large rank. Moeglin also showed that Adams' conjecture fails in low rank. Bakic and Hanzer showed that the failure can be managed: namely if Adams conjecture holds at some rank then it holds in any higher rank. In this talk\, we discuss how to understand the failure of Adams' conjecture in low rank and how to remedy it.
UID:117826-21840078@events.umich.edu
URL:https://events.umich.edu/event/117826
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240210T211220
DTSTART;TZID=America/Detroit:20240212T160000
DTEND;TZID=America/Detroit:20240212T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: Long mutation cycles
DESCRIPTION:A cluster algebra is a ring defined by combinatorial data: a quiver viewed up to mutation equivalence. The mutation graph of a (mutation) equivalence class of quivers has a vertex for each quiver and an edge between two vertices if their quivers are related by a mutation. A mutation cycle is a cycle in this graph. We show that already for 4-vertex quivers there are examples of mutation cycles that have arbitrarily large length and cannot be paved by shorter cycles\, and discuss other constructions of mutation cycles. This talk is based on joint work with Sergey Fomin.
UID:118702-21841491@events.umich.edu
URL:https://events.umich.edu/event/118702
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240208T144352
DTSTART;TZID=America/Detroit:20240212T161500
DTEND;TZID=America/Detroit:20240212T171500
SUMMARY:Workshop / Seminar:GLNT: Traces of random matrices over finite fields and cancellation in character sums
DESCRIPTION:Let X be a matrix drawn uniformly at random from GL_n(F_q)\, then one may conjecture that traces of powers of such matrices Tr(X^k) should have an asymptotically uniform distribution F_q. Further\, one may wonder how robust this phenomenon is and how large can k be. On the one hand\, this question is an analogue of a classic problem from random matrix theory\, and\, on the other hand\, it is intimately related to short character sums over function fields with the power k serving as the conductor. In our work\, we prove that the distribution of Tr(X^k) is indeed asymptotically uniform and that the respective short interval character sums exhibit cancellation for k = q^{o(n^2)}. This is a much wider range than one could hope to obtain for general characters\, and in fact\, this phenomenon seems to have no analogue over the integers. This is joint work with Ofir Gorodetsky.
UID:112526-21829080@events.umich.edu
URL:https://events.umich.edu/event/112526
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240128T145839
DTSTART;TZID=America/Detroit:20240213T160000
DTEND;TZID=America/Detroit:20240213T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: Parallel Algebraic Multigrid Methods for Higher-Order PDEs
DESCRIPTION:Existing algebraic multigrid (AMG) methods rely on assumptions about the near-kernel components of a given linear system. Namely\, that these components are \"smooth\" in the sense that they can be sufficiently approximated by few degrees of freedom. PDEs with higher order terms violate these assumptions\, causing an unbounded number of $V$-cycles for convergence. As an example\, we introduce a PDE that arises in kinetic-edge plasma simulation. This PDE contains an isotropic fourth-order term\, making existing methods infeasible. In this work\, we propose an $O(n)$ highly-parallelizable exact method to solve the system solely containing the isotropic fourth-order term. We then extend this algorithm to solve the original system\, including periodic boundary conditions. Our algorithm obtains drastic improvement over existing methods.
UID:117940-21840213@events.umich.edu
URL:https://events.umich.edu/event/117940
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240201T084524
DTSTART;TZID=America/Detroit:20240213T160000
DTEND;TZID=America/Detroit:20240213T170000
SUMMARY:Workshop / Seminar:Point counting over finite fields and the cohomology of moduli spaces of curves
DESCRIPTION:Algebraic geometry studies solution sets of polynomial equations. For instance\, over the complex numbers\, one may examine the topology of the solution set\, whereas over a finite field\, one may count its points. For polynomials with integer coefficients\, these two fundamental invariants are intimately related via cohomological comparison theorems and trace formulas for the action of Frobenius. I will discuss the general framework relating point counting over finite fields to topology of complex algebraic varieties and also present recent applications to the cohomology of moduli spaces of curves that resolve longstanding questions in algebraic geometry and confirm more recent predictions from the Langlands program.
UID:118237-21840683@events.umich.edu
URL:https://events.umich.edu/event/118237
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T114257
DTSTART;TZID=America/Detroit:20240214T110000
DTEND;TZID=America/Detroit:20240214T120000
SUMMARY:Presentation:Computing stable representations of graph configuration spaces
DESCRIPTION:An n-pointed configuration space of a topological space X parametrizes n distinct points in X. Configuration spaces of higher dimensional manifolds have been studied widely\, but less is known when X is a graph. We consider a family of graphs $G_n$ with compatible $S_n$-actions. Fixing the number of points k\, the homology groups of the k-configuration spaces of these graphs exhibit representation stability for many families. Examples include the star graphs\, complete graphs\, and the Kneser graphs. Our goal is to explicitly compute these stable representations. We use a discretized model for the configuration spaces developed by Abrams that has a cellular decomposition in terms of the combinatorics of the graphs and we perform our computations in the software system SageMath. We will present some partial results in the cases k=2 and G is a star graph and a complete graph. This is joint work with Eric Ramos.\n\n\nNote regarding location: The Pillsbury room is located on Floor 4M on the Psychology side of East Hall. To get to the room\, you enter the Psychology side of East Hall from the Church Street entrance and before you get into the Psych atrium\, there is an elevator to your left. Take the elevator to Floor 4M and the elevator opens into the room.
UID:117206-21838823@events.umich.edu
URL:https://events.umich.edu/event/117206
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240211T185731
DTSTART;TZID=America/Detroit:20240214T143000
DTEND;TZID=America/Detroit:20240214T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Properness and projectivity of toric varieties
DESCRIPTION:Continuing from last week\, we will continue discussing properness and projectivity of toric varieties. Along the way\, we will study the divisors and line bundles on toric varieties with some explicit examples.
UID:118713-21841502@events.umich.edu
URL:https://events.umich.edu/event/118713
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240209T150916
DTSTART;TZID=America/Detroit:20240214T150000
DTEND;TZID=America/Detroit:20240214T160000
SUMMARY:Workshop / Seminar:Student CA Seminar - Social Hour
DESCRIPTION:Join us for a social hour with snacks\, board games\, and math-themed Valentine's Day cards!\n\n(Image credit: Anna Brosowsky)
UID:118660-21841377@events.umich.edu
URL:https://events.umich.edu/event/118660
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240209T234339
DTSTART;TZID=America/Detroit:20240214T150000
DTEND;TZID=America/Detroit:20240214T155000
SUMMARY:Workshop / Seminar:Student Number Theory: Period integrals of automorphic forms and distinction problems
DESCRIPTION:In this talk we are going to introduce the theory of period integrals. In particular\, we are going to see many interplays between local and global distinction problems.
UID:118697-21841415@events.umich.edu
URL:https://events.umich.edu/event/118697
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240206T214425
DTSTART;TZID=America/Detroit:20240214T160000
DTEND;TZID=America/Detroit:20240214T173000
SUMMARY:Workshop / Seminar:Algebraic Geometry Seminar: Towards a geometric version of the monodromy conjecture
DESCRIPTION:The monodromy conjecture of Denef—Loeser predicts that given a complex polynomial f\, and any pole s of its motivic zeta function\, exp(2πis) is a \"monodromy eigenvalue\" associated to f. In this talk I will formulate a geometric version of the conjecture and elaborate on ongoing work\, starting from the case of Newton non-degenerate hypersurfaces. These are hypersurface singularities whose singularities are governed\, up to a certain extent\, by faces of their Newton polyhedra. The extent to which the former is governed by the latter is a key aspect of the conjecture. If time permits\, I will also sketch a recent pursuit to reduce the conjecture to a setting that is slightly more general than the case of Newton non-degenerate hypersurfaces.
UID:115340-21834474@events.umich.edu
URL:https://events.umich.edu/event/115340
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T010009
DTSTART;TZID=America/Detroit:20240214T160000
DTEND;TZID=America/Detroit:20240214T173000
SUMMARY:Workshop / Seminar:Logic Seminar: Functorial Semantics of Horn theories\, continued
DESCRIPTION:We continue from last week by describing a hyperdoctrine for equational theories. Then with an eye towards full first-order logic\, we discuss the Frobenius and Beck-Chevalley conditions.
UID:118721-21841526@events.umich.edu
URL:https://events.umich.edu/event/118721
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T151206
DTSTART;TZID=America/Detroit:20240215T160000
DTEND;TZID=America/Detroit:20240215T170000
SUMMARY:Workshop / Seminar:Versal deformations and algebraization
DESCRIPTION:TBA
UID:118755-21841567@events.umich.edu
URL:https://events.umich.edu/event/118755
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240206T083701
DTSTART;TZID=America/Detroit:20240216T090000
DTEND;TZID=America/Detroit:20240216T100000
SUMMARY:Presentation:Psychology Methods Hour: \"Uncovering urgency in daily life: Testing a novel method for assessing affect-impulsivity cooccurrence in momentary data\"
DESCRIPTION:Impulsivity and urgency\, a facet of impulsivity defined as the tendency to engage in impulsive behavior when experiencing strong emotions\, have wide-ranging implications for physical and mental health. Research on urgency\, however\, is at a crossroads. On the one hand\, there is an extensive body of research on trait self-reports of urgency\, suggesting that urgency is a valid and robust construct. On the other hand\, more recent work using ambulatory assessment methods has suggested that trait self-reports of urgency are unrelated to state urgency\, assessed as the covariance between people’s experienced emotions and impulsivity in the moment. In this Methods Hour talk\, we will discuss some of the challenges with assessing urgency in the moment as well as the potential implications of a novel conceptualization of state urgency. Are state and trait urgency different constructs? Are trait measures of urgency truly capturing the theorized construct? How is state urgency best assessed in the moment?
UID:116999-21838441@events.umich.edu
URL:https://events.umich.edu/event/116999
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Psychology
LOCATION:East Hall - 4464
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240201T113228
DTSTART;TZID=America/Detroit:20240216T150000
DTEND;TZID=America/Detroit:20240216T160000
SUMMARY:Lecture / Discussion:AIM Seminar: Inverse wave scattering via data driven reduced order modeling
DESCRIPTION:Abstract: This talk is concerned with the following inverse problem for the wave equation: Determine the variable wave speed from data gathered by a collection of sensors\, which emit probing signals and measure the generated backscattered waves. Inverse backscattering is an interdisciplinary field driven by applications in geophysical exploration\, radar imaging\, non-destructive evaluation of materials\, etc. There are two types of methods:\n\n(1) Qualitative (imaging) methods\, which address the simpler problem of locating reflective\nstructures in a known host medium.\n\n(2) Quantitative methods\, also known as velocity estimation. Typically\, velocity estimation is\nformulated as a PDE constrained optimization\, where the data are fit in the least squares sense by\n\nthe wave computed at the search wave speed. The increase in computing power has lead to growing interest in this approach\, but there is a fundamental impediment\, which manifests especially for high frequency data: The objective function is not convex and has numerous local minima even in the absence of noise. The main goal of the talk is to introduce a novel approach to\nvelocity estimation\, based on a reduced order model (ROM) of the wave operator. The ROM is called\ndata driven because it is obtained from the measurements made at the sensors. The mapping between these measurements and the ROM is nonlinear\, and yet the ROM can be computed efficiently using methods from numerical linear algebra. More importantly\, the ROM can be used to define a better objective function for velocity estimation\, so that gradient based optimization can succeed even for a poor initial guess.\n\n(Joint work with Josselin Garnier\, Alexander Mamonov and John Zimmerling)\n\nContact: AIM Seminar Organizers
UID:114764-21833579@events.umich.edu
URL:https://events.umich.edu/event/114764
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240211T175731
DTSTART;TZID=America/Detroit:20240216T150000
DTEND;TZID=America/Detroit:20240216T160000
SUMMARY:Workshop / Seminar:Semiabelian degeneration of abelian varieties
DESCRIPTION:A semiabelian scheme over a variety X is a smooth group variety G over X whose fibers are extensions of an abelian variety by a torus. I will discuss the ways that abelian varieties can degenerate into semiabelian varieties\, following Faltings and Chai\, and maybe some applications to compactifications of the moduli of abelian varieties.
UID:118708-21841497@events.umich.edu
URL:https://events.umich.edu/event/118708
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240123T131138
DTSTART;TZID=America/Detroit:20240216T150000
DTEND;TZID=America/Detroit:20240216T160000
SUMMARY:Workshop / Seminar:Tensor categories for Sets and Trees
DESCRIPTION:Recently\, Andrew Snowden and Nate Harman introduced a new technique for constructing tensor categories using some model-theoretic gadgets. The key ingredients are a group and a tensorial measure on this group. Interesting examples come from automorphism groups of \"big\" combinatorial objects. Noticeably\, the corresponding measures can be defined and computed via combinatorics of finite counterparts of these \"big\" objects. \n\nIn this talk\, I will give a friendly introduction to the topic and then focus on examples: \nDeligne’s categories Rep(S_t) corresponding to plain sets and arboreal categories Rep(T_t) corresponding to trees.
UID:117444-21839319@events.umich.edu
URL:https://events.umich.edu/event/117444
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T090319
DTSTART;TZID=America/Detroit:20240216T160000
DTEND;TZID=America/Detroit:20240216T170000
SUMMARY:Workshop / Seminar:GEOMETRY SEMINAR : Intro to higher-rank measure rigidity and the Einsieder-Lindenstrauss theorem
DESCRIPTION:I will try to explain the fundamental strategy of Katok-Spatzier for higher-rank measure rigidity\, highlighting the crucial role played by leafwise measures.\n\nThen we will state the recent measure rigidity theorem of Einsiedler-Lindenstrauss and try to provide an overview of the proof\, indicating the steps and the constructions which will be presented later in the seminar. The talk should be (essentially) accessible and independent from the previous talk by Ralf.
UID:118720-21841525@events.umich.edu
URL:https://events.umich.edu/event/118720
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240202T162325
DTSTART;TZID=America/Detroit:20240216T160000
DTEND;TZID=America/Detroit:20240216T173000
SUMMARY:Workshop / Seminar:Preprint Algebraic Geometry Seminar: Bernstein-Sato theory modulo p^m\, after Bitoun and Quinlan-Gallego
DESCRIPTION:TBA
UID:118316-21840878@events.umich.edu
URL:https://events.umich.edu/event/118316
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240221T144511
DTSTART;TZID=America/Detroit:20240219T110000
DTEND;TZID=America/Detroit:20240219T132000
SUMMARY:Lecture / Discussion:Foundations and Frontiers Speaker Series
DESCRIPTION:Sean Trott is an Assistant Professor at the University of California\, San Diego. He holds a joint appointment in Cognitive Science and Computational Social Science. His research focuses on how humans and machines understand language\, and makes use of Large Language Models (LLMs) to test hypotheses about human cognition.\n\nUPDATE: Sean Trott will be joining us virtually for this event\, the presentation will still take place in East Hall 4448.\n\nSchedule\n11:00-11:30 am Foundations Presentation\n11:30-11:45 am Q & A\n—15 minute pizza break—\n12:00-12:50 pm Frontiers Presentation\n12:50-1:20 pm Q & A\n\nPresentation Abstract\nFoundations: Many debates in Cognitive Science—such as whether certain cognitive capacities are innate\, or acquired through specific experiential input—are entrenched and difficult to resolve. A new paradigm attempts to address these debates using Large Language Models (LLMs) to test competing theories of human cognition. In particular\, because (most) LLMs are trained on linguistic input alone\, they serve as useful baselines: measures of what kinds of behaviors and capacities could in principle emerge purely from exposure to statistical patterns in language. In this talk\, I discuss the motivations for such an approach\, and briefly survey several examples from the literature. Finally\, I discuss the relevant trade-offs and considerations that might inform a researcher's decision about whether to use LLMs in their own research\, including: the amount (and quality) of data an LLM has been trained on\, issues of construct validity\, and multimodal models.\n\nFrontiers: Humans often reason about the mental states of others\, even when those mental states diverge from their own. The ability to reason about false beliefs—part of the broader constellation abilities that make up \"Theory of Mind\"—is viewed by many as playing a crucial role in social cognition. Yet there is considerable debate about whether this ability comes from. Some theories emphasize the role of innate biological endowments\, while others emphasize the role of experience. In this talk\, I consider a hypothesis about a specific kind of experience: language. To test this \"language exposure hypothesis\"\, I use GPT-3\, a Large Language Model (LLM) trained on linguistic input alone\, and ask whether and to what extent such a system displays evidence consistent with Theory of Mind. The LLM displays above-chance performance on a number of tasks\, but also falls short of human performance in multiple cases. I conclude by discussing the implications of these results for the language exposure hypothesis specifically\, and for research on Theory of Mind more generally.
UID:117370-21839225@events.umich.edu
URL:https://events.umich.edu/event/117370
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Free,Language
LOCATION:East Hall - 4448
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240218T204144
DTSTART;TZID=America/Detroit:20240219T150000
DTEND;TZID=America/Detroit:20240219T160000
SUMMARY:Workshop / Seminar:RTG NT: Polynomial factorization modulo many primes
DESCRIPTION:Abstract: The fastest known deterministic algorithms for factorising polynomials in F_p[x] have a worst-case runtime that is exponential in log p. We will discuss a new deterministic algorithm which factorises an integer polynomial modulo many primes simultaneously with amortised runtime that is polynomial in log p. Based on joint work with David Harvey.
UID:117827-21840079@events.umich.edu
URL:https://events.umich.edu/event/117827
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240208T151035
DTSTART;TZID=America/Detroit:20240219T160000
DTEND;TZID=America/Detroit:20240219T170000
SUMMARY:Workshop / Seminar:ISRMT seminar: Ablowitz-Ladik lattice and the Circular β-ensemble: a (kind of) surprising connection
DESCRIPTION:In this talk\, we focus on the interplay between the theory of integrable systems\, and random matrix theory.\nThis connection was first realized by H. Spohn\, who was able to compute the density of states for the Toda lattice by connecting it to the corresponding one of the Gaussian β ensemble\, a well known random matrix model. The computation of this quantity enabled him to apply the theory of generalized hydrodynamics\, so to compute the correlation functions for the Toda lattice.\nIn this talk\, I consider another integrable model\, namely the Ablowitz-Ladik lattice\; I introduce the Generalized Gibbs ensemble for this lattice\, and I relate it with the so-called Circular β ensemble\, a classical random matrix model for unitary matrices. This allows us to compute explicitly the density of states for the Ablowitz-Ladik lattice in terms of the one of this random matrix ensemble.\nThis talk is mainly based on these two papers:\n\nG. M. \, and T. Grava: Generalized Gibbs ensemble of the Ablowitz-Ladik lattice\, circular β- ensemble and double confluent Heun equation. Communication in Mathematical Physics. DOI: 10.1007/s00220-023-04642-8\n\nG. M.\, and R. Memin: Large Deviations for Ablowitz-Ladik lattice\, and the Schur flow. Electronic Journal of Probability. DOI: 10.1214/23-EJP941
UID:117622-21839714@events.umich.edu
URL:https://events.umich.edu/event/117622
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - EH1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240218T165051
DTSTART;TZID=America/Detroit:20240219T160000
DTEND;TZID=America/Detroit:20240219T170000
SUMMARY:Meeting:Quantitative Transversal Theorems in the Plane
DESCRIPTION:Helly's theorem is a foundational result in geometric combinatorics providing a condition for the non-emptiness of the intersection of a collection of convex sets in Euclidean space. Hadwiger's theorem is a variant of Helly-type theorems involving common transversals to families of convex sets instead of common intersections. In this talk\, we discuss these theorems\, as well as a quantitative and colorful version of Hadwiger's theorem on the plane.
UID:119011-21842030@events.umich.edu
URL:https://events.umich.edu/event/119011
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Graduate Students,Mathematics,seminar
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T161335
DTSTART;TZID=America/Detroit:20240219T160000
DTEND;TZID=America/Detroit:20240219T170000
SUMMARY:Lecture / Discussion:Ziwet Lecture I | Morrey's theory and direct methods of the calculus of variations
DESCRIPTION:In the middle of the last century\, Charles Morrey introduced the notions of poly-convexity\, rank-one-convexity and quasi-convexity functions\, to study variational problems. While the first two notions are local conditions\, the third one which turned out to be the most important one\, is a non local and poorly understood notion. In this talk we comment on Morrey's conjecture and Iwaniec's conjecture on the Beurling-Ahlfors Transform.
UID:115812-21835662@events.umich.edu
URL:https://events.umich.edu/event/115812
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:AEM Featured,Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240213T091155
DTSTART;TZID=America/Detroit:20240219T161500
DTEND;TZID=America/Detroit:20240219T171500
SUMMARY:Workshop / Seminar:GLNT: Random multiplicative functions: old and new results
DESCRIPTION:Random multiplicative functions are probabilistic models for important arithmetic functions in number theory\, e.g. Mobius function\, Dirichlet characters. In this talk\, I would like to introduce the topic and emphasize some recent developments. Part of the talk is based on joint works with Angelo\, Harper\, and Soundararajan.
UID:112527-21829081@events.umich.edu
URL:https://events.umich.edu/event/112527
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240219T100701
DTSTART;TZID=America/Detroit:20240220T160000
DTEND;TZID=America/Detroit:20240220T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: In-Duck-Tion
DESCRIPTION:Show up and find out!
UID:119030-21842049@events.umich.edu
URL:https://events.umich.edu/event/119030
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Graduate School,Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T161403
DTSTART;TZID=America/Detroit:20240220T160000
DTEND;TZID=America/Detroit:20240220T170000
SUMMARY:Workshop / Seminar:Ziwet Lecture II | On differentiability in the Wasserstein space
DESCRIPTION:We consider P₂(Rᵈ)\, the set of Borel probability measures of finite second moments on Rᵈ\, which we endow with the Wasserstein metric W₂. It is well–known that P₂(Rᵈ)\, W₂)\, is isometric to a quotient space of the Hilbert space H of square-integrable random variables on (0\, 1)ᵈ. We elucidate the connection between various notions of differentiability in the Wasserstein space: some have been introduced intrinsically (in the Wasserstein space\, by using typical objects from the theory of Optimal Transport). Another notion is extrinsic and arises from the identification of the Wasserstein space with the Hilbert space of square-integrable random variables on a non-atomic probability space.
UID:107836-21817093@events.umich.edu
URL:https://events.umich.edu/event/107836
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:AEM Featured,Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240220T204339
DTSTART;TZID=America/Detroit:20240220T200000
DTEND;TZID=America/Detroit:20240220T210000
SUMMARY:Lecture / Discussion:MATH LCIT CONVERSATION
DESCRIPTION:In this meeting\, we will continue our discussion of Reinholtz's book\, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester\, we started discussion of the text\, discussing the material through the beginning of chapter 3 (roughly\, sections 1.1\, 2.3.5-2.4\, and 3.1-3.2). For this meeting\, we will discuss sections 3.3 through the end of chapter 4. Meetings of the LCIT occur in East Hall room 4866.
UID:119153-21842270@events.umich.edu
URL:https://events.umich.edu/event/119153
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Diversity Equity And Inclusion,Education,Mathematics,Teaching And Learning
LOCATION:East Hall - EH 4866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240220T204339
DTSTART;TZID=America/Detroit:20240220T200000
DTEND;TZID=America/Detroit:20240220T210000
SUMMARY:Lecture / Discussion:MATH LCIT CONVERSATION
DESCRIPTION:In this meeting\, we will continue our discussion of Reinholtz's book\, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester\, we started discussion of the text\, discussing the material through the beginning of chapter 3 (roughly\, sections 1.1\, 2.3.5-2.4\, and 3.1-3.2). For this meeting\, we will discuss sections 3.3 through the end of chapter 4. Meetings of the LCIT occur in East Hall room 4866.
UID:119153-21842271@events.umich.edu
URL:https://events.umich.edu/event/119153
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Diversity Equity And Inclusion,Education,Mathematics,Teaching And Learning
LOCATION:East Hall
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240205T205455
DTSTART;TZID=America/Detroit:20240221T110000
DTEND;TZID=America/Detroit:20240221T120000
SUMMARY:Presentation:Stability and Periodicity Phenomena for Cohomology of Sheaves
DESCRIPTION:The problem of computing the cohomology of line bundles on flag varieties in arbitrary characteristic has remained an open question despite decades of study and many important results. A more recent perspective on this problem has instead focused on stability\; more precisely\, how does the cohomology of a fixed line bundle vary as the dimension of the ambient flag becomes arbitrarily large? In recent joint work with Raicu\, we answer this: the cohomology is eventually modeled by a fixed polynomial functor\, depending only on the weight of the line bundle. Moreover\, for certain classes of weights\, we can show that these stability functors exhibit remarkable periodicity properties determined by the characteristic of the underlying field. In this talk\, we will see some of the background and tools that go into these results\, including an unexpected connection to a long-open problem of Akin--Buchsbaum on \"universal\" categorifications of the Jacobi-Trudi identity.
UID:117200-21838817@events.umich.edu
URL:https://events.umich.edu/event/117200
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240218T172123
DTSTART;TZID=America/Detroit:20240221T143000
DTEND;TZID=America/Detroit:20240221T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Introduction to Symplectic Toric Manifolds and the Moment Map
DESCRIPTION:In this talk I will will be looking at toric geometry from a symplectic point of view. We will begin by looking at symplectic manifolds. There are natural actions of Lie groups on such manifolds and we will define certain maps called moment maps. In the case of torus actions\, we will discuss results by Atiyah-Guillemin-Sternberg and Delzant\, relating convex polytopes and toric manifolds\, via moment maps.
UID:119013-21842033@events.umich.edu
URL:https://events.umich.edu/event/119013
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240216T202217
DTSTART;TZID=America/Detroit:20240221T150000
DTEND;TZID=America/Detroit:20240221T155000
SUMMARY:Workshop / Seminar:Student Number Theory: ABC Conjecture in Function Fields
DESCRIPTION:The rings Z and F_q[T] share many properties in common\, so one might try to study number theory over F_q[T]. A (global) function field is a finite extension of F_q(T)\, just as a number field is a finite extension of Q. In this talk I will discuss the function field analogy. In particular\, we will sketch a proof of an analogue of the ABC conjecture and Fermat’s last theorem in function fields.
UID:118997-21842012@events.umich.edu
URL:https://events.umich.edu/event/118997
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240214T221746
DTSTART;TZID=America/Detroit:20240221T160000
DTEND;TZID=America/Detroit:20240221T173000
SUMMARY:Workshop / Seminar:Algebraic Geometry Seminar: Generic character sheaves on parahoric subgroups
DESCRIPTION:Lusztig's theory of character sheaves for connected reductive groups is one of the most important developments in representation theory in the last few decades. In this talk\, I will describe some basic algebro-geometric techniques underlying this theory and explain the need for a theory of character sheaves on jet schemes of reductive groups from the perspective of the Langlands program. Recently\, R. Bezrukavnikov and I have developed the \"generic\" part of this desired theory. In the simplest nontrivial case\, this resolves a conjecture of Lusztig and produces perverse sheaves on jet schemes compatible with parahoric Deligne--Lusztig induction.
UID:118704-21841493@events.umich.edu
URL:https://events.umich.edu/event/118704
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240214T144504
DTSTART;TZID=America/Detroit:20240221T160000
DTEND;TZID=America/Detroit:20240221T172000
SUMMARY:Workshop / Seminar:RTG GeomDynTop Seminar: Fibrations by pencils of quadrics and maximal representations
DESCRIPTION:The hyperbolic 3-manifold associated to a Fuchsian \nrepresentation of a surface group admits a fibration over the surface with geodesic fibers that extends to a fibration of the conformal boundary. This also holds for almost Fuchsian representations\, but not in general for quasi-Fuchsian representations.\n\nI will present an analog of this picture for representations of surface groups into Sp(2n\,R). Among these representations\, there exists a union of connected components containing only discrete and faithful representations\, called maximal representations. We will consider fibrations by projective codimension $2$ subspaces of a projective convex set containing the symmetric space of Sp(2n\,R). These subspaces are described by pencils of quadrics\, and we will see that one can characterize maximal representations by the existence of such a continuous fibration\, satisfying some additional properties. The hyperbolic 3-manifold associated to a Fuchsian representation of a surface group admits a fibration over the surface with geodesic fibers that extends to a fibration of the conformal boundary. This also holds for almost Fuchsian representations\, but not in general for quasi-Fuchsian representations.
UID:118235-21840682@events.umich.edu
URL:https://events.umich.edu/event/118235
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T161453
DTSTART;TZID=America/Detroit:20240221T160000
DTEND;TZID=America/Detroit:20240221T170000
SUMMARY:Lecture / Discussion:Ziwet Lecture III | Hamilton-Jacobi equations in the Wasserstein space
DESCRIPTION:We show that the classical theory of well-posedness for viscosity solutions for Hamilton-Jacobi equations in infinite-dimensional Hilbert spaces is brought to bear on well-posedness for Hamilton-Jacobi equations in the Wasserstein space.
UID:115813-21835663@events.umich.edu
URL:https://events.umich.edu/event/115813
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:AEM Featured,Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20231220T224222
DTSTART;TZID=America/Detroit:20240221T170000
DTEND;TZID=America/Detroit:20240221T180000
SUMMARY:Workshop / Seminar:On Perturbations of Preferences and Indifference Price Invariance
DESCRIPTION:We investigate indifference pricing under perturbations of preferences in small and large markets. We establish stability results for small perturbations of preferences\, where the latter can be stochastic. We obtain a sharp condition in terms of the associated concave and convex envelopes and provide counterexamples demonstrating that\, in general\, stability fails. Next\, we investigate a class of models where the indifference price does not depend on the preferences or the initial wealth. Here\, under the existence of an equivalent separating measure\, in the settings of deterministic preferences\, we show that the class of indifference price invariant models is the class of models where the dual domain is stochastically dominant of the second order. We also provide a counterexample showing that\, in general\, this result does not hold over stochastic preferences\, where instead\, we show that the indifference price invariant models are complete models (in both small and large markets). In the process\, we establish a theorem of independent interest on the stability of the optimal investment problem under perturbations of preferences. Our results are new in both small and large markets\, and thus\, in particular\, we introduce large stochastically dominant models\, give examples of such models\, and characterize them as the indifference price invariant ones over deterministic preferences.
UID:110937-21825884@events.umich.edu
URL:https://events.umich.edu/event/110937
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240118T164953
DTSTART;TZID=America/Detroit:20240222T160000
DTEND;TZID=America/Detroit:20240222T173000
SUMMARY:Workshop / Seminar:Artin's axioms 1
DESCRIPTION:TBA
UID:117417-21839276@events.umich.edu
URL:https://events.umich.edu/event/117417
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240122T220935
DTSTART;TZID=America/Detroit:20240222T160000
DTEND;TZID=America/Detroit:20240222T170000
SUMMARY:Workshop / Seminar:Commutative Algebra Seminar: The Total Rank Conjecture in Characteristic Two
DESCRIPTION:The total rank conjecture is a coarser version of the Buchsbaum-Eisenbud-Horrocks conjecture which\, loosely stated\, predicts that modules with large annihilators must also have \"large\" syzygies. In 2017\, Walker proved that the total rank conjecture holds over rings of odd characteristic\, using techniques that heavily relied on the invertibility of 2. In this talk\, I will speak on joint work with Walker where we settle (and generalize) the total rank conjecture over k-algebras of arbitrary characteristic. Our techniques take advantage of the classical Dold-Kan correspondence and allow us to prove an even stronger version of the total rank conjecture when the field k has characteristic 2.
UID:117313-21839159@events.umich.edu
URL:https://events.umich.edu/event/117313
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240218T182703
DTSTART;TZID=America/Detroit:20240222T160000
DTEND;TZID=America/Detroit:20240222T165000
SUMMARY:Workshop / Seminar:Student Dyn/Geo/Top: The Nerve Lemma & Spectral Sequences
DESCRIPTION:The Nerve Lemma is a useful tool that\, under some hypotheses\, lets one compute the homology of a space in terms of a simplicial complex built from an open cover of the space. In this talk we shall see the statement of this lemma\, a proof glimpse by analyzing a certain double complex\, and if time permits\, a proof sketch via (a gentle introduction to) spectral sequences.
UID:119020-21842041@events.umich.edu
URL:https://events.umich.edu/event/119020
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240214T141709
DTSTART;TZID=America/Detroit:20240223T150000
DTEND;TZID=America/Detroit:20240223T160000
SUMMARY:Lecture / Discussion:AIM Seminar: Integral Equation Calculations for Electrostatics of Solvated Biomolecules
DESCRIPTION:Abstract: I will present a new version of the treecode-accelerated boundary integral Poisson-Boltzmann solver which computes the electrostatic potential on the molecular surface of a solvated biomolecule using a well-conditioned integral equation formulation. The new version utilizes the NanoShaper surface triangulation code\, node-patch boundary integral discretization\, a block preconditioner\, and a GPU-accelerated fast multipole method based on barycentric Lagrange interpolation and dual tree traversal. Numerical results for protein 1A63 and two viral capsids (Zika\, H1N1) demonstrate the code’s accuracy and efficiency. I will also discuss an extension of this approach to the Poisson-Nernst-Planck model for ion transport through channel proteins in cell membranes. This talk reports on joint work with Zhen Chao (Western Washington University)\, Weihua Geng (Southern Methodist University)\, Svetlana Tlupova (Farmingdale State College)\, Nathan Vaughn (LANL)\, Lei Wang (U-Wisconsin\, Milwaukee)\, and Leighton Wilson (Cerebras Systems).\n\nContact: AIM Seminar Organizers
UID:114766-21833581@events.umich.edu
URL:https://events.umich.edu/event/114766
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240217T193634
DTSTART;TZID=America/Detroit:20240223T160000
DTEND;TZID=America/Detroit:20240223T170000
SUMMARY:Workshop / Seminar:GEOMETRY SEMINAR: Intro to higher-rank measure rigidity and the Einsiedler-Lindenstrauss theorem
DESCRIPTION:We will state the recent measure rigidity theorem of Einsiedler-Lindenstrauss and try to provide an overview of the proof\, indicating the steps and the constructions which will be presented later in the seminar. The talk should be (essentially) accessible and independent from the previous talks.
UID:119003-21842021@events.umich.edu
URL:https://events.umich.edu/event/119003
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240205T112741
DTSTART;TZID=America/Detroit:20240223T160000
DTEND;TZID=America/Detroit:20240223T173000
SUMMARY:Workshop / Seminar:Preprint Algebraic Geometry Seminar: the Bakker-Schnell proof of Hwang's theorem on base manifolds of Lagrangian fibrations\,
DESCRIPTION:TBA
UID:118377-21840987@events.umich.edu
URL:https://events.umich.edu/event/118377
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240219T093112
DTSTART;TZID=America/Detroit:20240228T160000
DTEND;TZID=America/Detroit:20240228T173000
SUMMARY:Workshop / Seminar:Special Algebraic Geometry Seminar: Refined transversality and equivariant positivity
DESCRIPTION:The standard Kleiman-Bertini transversality theorems say that if a variety is homogeneous with respect to the action of an algebraic group\, then this action moves any two subvarieties into transverse position. I will describe refinements which treat cases where the action is not transitive\, along with an application to the positivity of cohomology and K-theory classes of subvarieties of a generalized flag variety.
UID:118350-21840926@events.umich.edu
URL:https://events.umich.edu/event/118350
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240301T121924
DTSTART;TZID=America/Detroit:20240304T150000
DTEND;TZID=America/Detroit:20240304T160000
SUMMARY:Workshop / Seminar:RTG NT: Modular degrees of elliptic curves over function fields
DESCRIPTION:Abstract: The degree of the modular parametrization of an elliptic curve is an important invariant that is related to congruences of modular forms. In the case of an elliptic curve E over Q\, the degrees of parameterizations of E by different Shimura curves are related to each other through Tamagawa numbers. We will discuss the analogous situation for elliptic curves over function fields\, which admit different parameterizations by moduli of Drinfeld-Stuhler-modules.
UID:117828-21840080@events.umich.edu
URL:https://events.umich.edu/event/117828
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240303T225313
DTSTART;TZID=America/Detroit:20240304T160000
DTEND;TZID=America/Detroit:20240304T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: Introduction to Combinatorial Hopf Algebras
DESCRIPTION:A combinatorial Hopf algebra is a graded connected Hopf algebra with finite-dimensional pieces equipped with a character. We will show that the quasi-symmetric (symmetric) functions can be made into a (cocommutative) combinatorial Hopf algebra and that it is the terminal object in the category of (cocommutative) combinatorial Hopf algebras. We will give examples of combinatorial Hopf algebras naturally arising from combinatorics and an application of this result to the study of affine Stanley symmetric functions.
UID:119596-21843051@events.umich.edu
URL:https://events.umich.edu/event/119596
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20230916T222120
DTSTART;TZID=America/Detroit:20240304T161500
DTEND;TZID=America/Detroit:20240304T173000
SUMMARY:Workshop / Seminar:GLNT
DESCRIPTION:TBA
UID:112529-21829083@events.umich.edu
URL:https://events.umich.edu/event/112529
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240220T204339
DTSTART;TZID=America/Detroit:20240305T110000
DTEND;TZID=America/Detroit:20240305T123000
SUMMARY:Lecture / Discussion:MATH LCIT CONVERSATION
DESCRIPTION:In this meeting\, we will continue our discussion of Reinholtz's book\, Equitable Teaching and Engaging Mathematics Teaching: A Guide to Disrupting Hierarchies in the Classroom. In our first meeting of the semester\, we started discussion of the text\, discussing the material through the beginning of chapter 3 (roughly\, sections 1.1\, 2.3.5-2.4\, and 3.1-3.2). For this meeting\, we will discuss sections 3.3 through the end of chapter 4. Meetings of the LCIT occur in East Hall room 4866.
UID:119153-21842269@events.umich.edu
URL:https://events.umich.edu/event/119153
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Diversity Equity And Inclusion,Education,Mathematics,Teaching And Learning
LOCATION:East Hall - 4866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240305T110339
DTSTART;TZID=America/Detroit:20240305T160000
DTEND;TZID=America/Detroit:20240305T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: Group Algebras
DESCRIPTION:How can we turn any group into an algebra? It’s simpler than you think. These objects also have some interesting applications and ties to representation theory and other algebraic areas of study.
UID:119697-21843420@events.umich.edu
URL:https://events.umich.edu/event/119697
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240304T142517
DTSTART;TZID=America/Detroit:20240305T170000
DTEND;TZID=America/Detroit:20240305T180000
SUMMARY:Workshop / Seminar:Student Analysis Seminar: General Relativity and the Einstein Equations
DESCRIPTION:From a mathematical viewpoint\, general relativity (GR) lies at the intersection of differential geometry and partial differential equations. It is the study of manifolds whose curvature obeys certain properties (dictated by the Einstein equations)\, and also of various quantities of interest on these manifolds. These quantities usually have physically significant interpretations\, and it is interesting to study how these quantities are affected by the underlying spacetime curvature. Since GR is a nonlinear theory\, the quantities themselves also influence the underlying curvature. This talk will be an introduction to the mathematical side of GR\, viewed from the lens of differential geometry and analysis.
UID:119406-21842687@events.umich.edu
URL:https://events.umich.edu/event/119406
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240125T084640
DTSTART;TZID=America/Detroit:20240306T100000
DTEND;TZID=America/Detroit:20240306T160000
SUMMARY:Fair / Festival:Psychology Regalia Fair
DESCRIPTION:Congrats University of Michigan Psychology Grads!\n\nFor all graduating Psych and BCN students\, come order your cap & gown\, graduation announcements\, diploma frame\, and official class ring at the Grad Fair.\n\nYou can also order your regalia online at herff.ly/umpsych.
UID:103185-21836429@events.umich.edu
URL:https://events.umich.edu/event/103185
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Biopsychology\, Cognition\, And Neuroscience (Bcn),Commencement,Graduate Students,Graduation,Psychology,Undergraduate Students
LOCATION:East Hall - Psychology 1st Floor Atrium
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240227T144118
DTSTART;TZID=America/Detroit:20240306T110000
DTEND;TZID=America/Detroit:20240306T120000
SUMMARY:Presentation:`Puncture' stability for the (co)homology of mapping class groups
DESCRIPTION:In this talk\, we will consider the mapping class group of a compact surface with n punctures\, and its pure subgroup consisting of mapping classes that fix the punctures pointwise. We will describe two stability phenomena that the (co)homology of these families of groups (indexed by the number n of punctures) exhibit. When the surface has non-empty boundary\, the `puncture' homological stability of the family of mapping class groups is closely related with the representation stability of the sequence of homology groups of the pure mapping class groups. If time permits\, we will explain this relation and how it could be used to obtain new results.
UID:117201-21838818@events.umich.edu
URL:https://events.umich.edu/event/117201
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240303T122958
DTSTART;TZID=America/Detroit:20240306T143000
DTEND;TZID=America/Detroit:20240306T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Chow Group and Cohomology of Simplicial Toric Varieties
DESCRIPTION:We will review the basic theory of Chow groups and study its intersection product for simplicial toric varieties. We will show that the Chow group endowed with the intersection product is isomorphic to the cohomology ring\, thus showing various corollaries such as relating Betti numbers and the number of cones in the associated fan. Finally\, we will show a description of the cohomology ring in terms of generators and an ideal of relations. We will also prove analogous but stronger statements for nonsingular toric varieties.
UID:119595-21843050@events.umich.edu
URL:https://events.umich.edu/event/119595
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240305T110511
DTSTART;TZID=America/Detroit:20240306T150000
DTEND;TZID=America/Detroit:20240306T160000
SUMMARY:Workshop / Seminar:Student CA Seminar: Commutative algebra in the Verlinde category
DESCRIPTION:I'll define the Verlinde category\, which is a novel tensor category in characteristic p > 0 whose objects cannot be realized as vector spaces in a precise sense. One can still make sense of commutative rings in the Verlinde category\, with the added challenge that one cannot really talk about elements in the ring. We will see that\, like in the category of vector spaces\, the Hilbert's basis theorem holds\, i.e.\, finitely generated algebras are noetherian\, a result due to Venkatesh.
UID:117318-21841896@events.umich.edu
URL:https://events.umich.edu/event/117318
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240301T182458
DTSTART;TZID=America/Detroit:20240306T150000
DTEND;TZID=America/Detroit:20240306T155000
SUMMARY:Workshop / Seminar:Student Number Theory: A brief introduction to the Langlands correspondence
DESCRIPTION:In this talk\, we will motivate and introduce the Langlands correspondence (in vague terms). We will begin by defining Hasse-Weil L-functions from a point-counting perspective\, before seeing how we can think of them as arising from Galois representations. To see how these constructions might be related to automorphic representations\, we will begin by considering the relationship between elliptic curves and cuspidal Hecke eigenforms described by the modularity theorem. We will then think about how to define L-functions for automorphic representations more generally\, and how they may relate to Hasse-Weil L-functions. Finally\, we will use Langlands’ formalism around L-functions of automorphic representations to think about a relationship between automorphic representations of different groups\, as formulated in the functoriality conjecture.
UID:119549-21842999@events.umich.edu
URL:https://events.umich.edu/event/119549
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240219T190611
DTSTART;TZID=America/Detroit:20240306T160000
DTEND;TZID=America/Detroit:20240306T173000
SUMMARY:Workshop / Seminar:Algebraic Geometry Seminar: Constructible exceptional bundles on P^3
DESCRIPTION:Exceptional vector bundles are a class of rigid bundles commonly found on Fano varieties with close connections to geometry and homological algebra. Foundational results of Drezet and Le Potier from the 1980s show that on the projective plane exceptional bundles have a deep and elaborate relationship with stable bundles in general. In this talk I will explore how these results in some ways extend and in other ways fail to extend to three-dimensional projective space\, and discuss several interesting open problems concerning exceptional bundles.
UID:115967-21835950@events.umich.edu
URL:https://events.umich.edu/event/115967
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240227T151454
DTSTART;TZID=America/Detroit:20240306T160000
DTEND;TZID=America/Detroit:20240306T173000
SUMMARY:Workshop / Seminar:Geom/Top RTG Seminar: On classifying spaces of mapping class groups
DESCRIPTION:Given a discrete group G and a family F of subgroups of G there is a G-CW complex that classifies G-CW complexes with isotropy contained in the family F. Such space is unique up to G-equivariant homotopy and is often called the classifying space of G for the family F. For the trivial family it is the universal cover of a K(G\,1) space\, and more generally\, classifying spaces for families play an important role in the classification of manifolds with a given fundamental group G. In this talk\, we will introduce these notions and survey what is known about classifying spaces for some families of subgroups of the mapping class group of an orientable surface of finite type. Time permitting\, we will discuss recent joint work with Porfirio León Álvarez and Luis Jorge Sánchez Saldaña in this topic.
UID:115726-21835436@events.umich.edu
URL:https://events.umich.edu/event/115726
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240212T151349
DTSTART;TZID=America/Detroit:20240307T160000
DTEND;TZID=America/Detroit:20240307T170000
SUMMARY:Workshop / Seminar:Artin's axioms 2
DESCRIPTION:TBA
UID:118756-21841568@events.umich.edu
URL:https://events.umich.edu/event/118756
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240304T033622
DTSTART;TZID=America/Detroit:20240307T160000
DTEND;TZID=America/Detroit:20240307T170000
SUMMARY:Workshop / Seminar:Commutative Algebra Seminar: On lengths of $\mathbb{F}_2[x\,y\,z]/(x^{d_1}\, y^{d_2}\,z^{d_3}\, x+y+z)$
DESCRIPTION:While the vector space dimension of the ring $k[x_1\, \dots\, x_n]/(x_1^{d_1}\, \dots\, x_n^{d_n})$ can easily be calculated as $\prod_{i=1}^n d_i$\, adding in an additional ideal generator $x_1+\dots+x_n$ greatly complicates the problem. In this talk\, I will present a formula for the vector space dimension of $\mathbb{F}_2[x\,y\,z]/(x^{d_1}\, y^{d_2}\,z^{d_3}\, x+y+z)$ when $d_1\,d_2\,d_3$ all lie between successive powers of $2$. Combining this with results of Chungsim Han\, we get a complete description of the vector space dimension of $\mathbb{F}_2[x\,y\,z]/(x^{d_1}\, y^{d_2}\,z^{d_3}\, x+y+z)$ for any $d_1\,d_2\,d_3$. This is joint work with Fiona Han\, Jenny Kenkel\, Daniel Li\, and Ashley Wiles (in fact\, this came out of a Winter 2023 LoG(M) project done by Fiona\, Daniel and Ashley\, where Jenny and I were the mentors).
UID:118092-21840501@events.umich.edu
URL:https://events.umich.edu/event/118092
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240304T130154
DTSTART;TZID=America/Detroit:20240307T160000
DTEND;TZID=America/Detroit:20240307T170000
SUMMARY:Workshop / Seminar:Differential Equations Seminar: Generic Naked Singularities in Vaidya Spacetimes
DESCRIPTION:The incoming Vaidya spacetimes are perhaps the simplest toy models for the dynamical formation of a Schwarzschild black hole from nonsingular initial conditions\, arising from the collapse of a spherically symmetric cloud of null dust. I'll discuss the structure of these spacetimes and demonstrate\, via the analysis of a simple ODE\, that they can also exhibit the formation of naked singularities\, singularities visible from infinity\, accompanying the black hole provided only that the null dust accumulates slowly. More pointedly\, I'll demonstrate that there is a sense in which the emergence of naked singularities is generic within this class of spacetimes. This observation is of note for the weak cosmic censorship conjecture\, a fundamental postulate as to the nature and extent of solutions to the Einstein equations when coupled to \"reasonable\" matter.
UID:118749-21841562@events.umich.edu
URL:https://events.umich.edu/event/118749
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240304T120124
DTSTART;TZID=America/Detroit:20240307T160000
DTEND;TZID=America/Detroit:20240307T165000
SUMMARY:Workshop / Seminar:Student Dyn/Geo/Top: Random Hyperbolic Surfaces with Long Boundaries
DESCRIPTION:In this talk\, I’ll discuss properties of random hyperbolic surfaces with long boundaries. I’ll first talk about what a random surface means in this context\, and introduce hyperbolic moduli spaces. I’ll then explain how the ‘spine graph construction’ allows us to relate random hyperbolic surfaces to random graphs\, before briefly discussing why this relation works and what we can use it to prove.
UID:119607-21843065@events.umich.edu
URL:https://events.umich.edu/event/119607
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240221T153457
DTSTART;TZID=America/Detroit:20240308T090000
DTEND;TZID=America/Detroit:20240308T100000
SUMMARY:Presentation:Psychology Methods Hour: \"Illustrating a Critical Quantitative approach to measurement with MIMIC models\"
DESCRIPTION:The emerging Critical Quantitative (Crit Quant) perspective is anchored by five guiding principles (i.e.\, foundation\, goals\, parity\, subjectivity\, and self-reflexivity) to mitigate racism and advance social justice. Within this broader methodological perspective\, sound measurement is foundational to the quantitative enterprise. Despite the problematic history of measurement\, it can be repurposed for critical and equitable ends. MIMIC (Multiple Indicator and Multiple Causes) models are a measurement strategy to simply and efficiently test whether a measure means the same thing and can be measured in the same way across groups (e.g.\, racial/ethnic and/or gender groups). This talk considers the affordances and limitations of MIMICs for critical quantitative methods\, by detecting and mitigating racial\, ethnic\, gendered\, and other forms of bias in items and in measures. Discussion topics will include the affordances of Crit Quant vs QuantCRiT (Quantitative Critical Race Theory) and how Crit Quant and MIMICs do (and don't) detect racism in psychological and social science measures.
UID:117003-21838444@events.umich.edu
URL:https://events.umich.edu/event/117003
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Psychology
LOCATION:East Hall - 4448
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240119T145122
DTSTART;TZID=America/Detroit:20240308T130000
DTEND;TZID=America/Detroit:20240308T150000
SUMMARY:Other:Pop Up Opportunity Hub Coaching
DESCRIPTION:Pop up coaching allows you to meet with an Opportunity Hub coach in a space that is convenient to you! This semester\, the Opportunity Hub and LSA Psychology are partnering to bring you pop up coaching in the East Hall Psychology Atrium. Pop up coaching is a great opportunity to make meaningful progress toward your professional goals within a shorter period of time\; especially if you are a little pressed for time and are looking for on-the-spot support. For example\, if you have a grad school\, internship\, or job application due in a week\, drop-in coaching may be ideal. Pop up coaching is also great for students who are looking to try coaching for the first time.\n\nThis event is open to ALL students!
UID:117244-21839444@events.umich.edu
URL:https://events.umich.edu/event/117244
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Biopsychology\, Cognition\, And Neuroscience (Bcn),Career,Graduate School,Psychology
LOCATION:East Hall - Psychology Atrium (North)
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240223T162908
DTSTART;TZID=America/Detroit:20240308T150000
DTEND;TZID=America/Detroit:20240308T160000
SUMMARY:Lecture / Discussion:AIM Seminar: Understanding the deformation of granular matter and its implications for granular locomotion
DESCRIPTION:Abstract: Granular matter\, being an assembly of discrete particles\, has complex mechanical behaviors emerging from the interactions of these particles\, which often have a disordered yet non-trivial spatial arrangement. Unlike crystalline materials\, the packing structure in a disordered material is often hard to describe mathematically\, which prohibits us from understanding the deformation from a structure-property point of view. In this presentation\, I will first present experimental results of the deformation of a layer of granular particles floating at an air-oil interface\, through which I can demonstrate the elasto-plastic nature of deformation in the quasi-static regime. Based on the experimental results\, a machine learning-based modeling framework was developed based on the interplay between elasticity\, packing structure\, and quasi-localized rearrangements of particles. The model can capture a ductile-to-brittle transition observed in the experimental system due to the change of particle properties.\n\nIn the second part of the talk\, I will demonstrate the implications of the complex mechanical behaviors of granular materials for locomotion. In this problem\, granular matter can be considered as a soft and yielding medium that interacts with a deforming body. I will show experimentally that a scallop-like swimmer with reciprocally flapping wings generates locomotion in granular matter\, which is often not possible in Newtonian liquids at low Reynolds numbers. We use X-ray imaging and discrete element method simulations to reveal the microscopic picture of how the wings interact with surrounding particles. The locomotion is enabled by a prolonged hysteresis in the material response that originates from a combination of jamming-induced material rigidity and plastic deformation of the free surface. Cooperative effects are observed when the two wings are in close proximity\, which potentially involves interaction of zones with jammed particles as well as heap building on the free surface.\n\nContact: Silas Alben
UID:114767-21833582@events.umich.edu
URL:https://events.umich.edu/event/114767
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240304T001005
DTSTART;TZID=America/Detroit:20240308T150000
DTEND;TZID=America/Detroit:20240308T160000
SUMMARY:Workshop / Seminar:Compactification of the Hurwitz Scheme
DESCRIPTION:We are motivated by the following problem: which curves are d-sheeted covering spaces of the projective line? We discuss the moduli space of d-sheeted coverings\, the *Hurwitz Scheme\,* together with a particular compactification due to Mumford and Harris. This compactification\, and its relationship to the compactification of the moduli space of genus g curves\, allows us to use graph-theoretic tools to help determine whether certain general curves are d-sheeted coverings of P^1.
UID:119597-21843052@events.umich.edu
URL:https://events.umich.edu/event/119597
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240222T111549
DTSTART;TZID=America/Detroit:20240308T150000
DTEND;TZID=America/Detroit:20240308T160000
SUMMARY:Workshop / Seminar:The deep locus in a cluster variety
DESCRIPTION:Cluster varieties are geometric objects corresponding to cluster algebras\; they have many open subsets called cluster tori. These tori cover almost all of the cluster variety\, but not quite all of it\; the \"deep locus\" is the part of the cluster variety which is not in any cluster torus. In joint work with Marco Castronovo\, Mikhail Gorsky and José Simental Rodríguez\, we conjecture a description of the deep locus\, and prove it for braid varieties on 2 and 3 strands. In this talk\, I will explain our conjecture\, and I will make clear what combinatorial problem we'd need to solve in order to prove this result for all braid varieties. I will not assume that the audience has seen cluster varieties or braid varieties before and\, indeed\, I hope that this talk will serve as a good introduction to those topics.
UID:118645-21841345@events.umich.edu
URL:https://events.umich.edu/event/118645
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - East Hall 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240302T220353
DTSTART;TZID=America/Detroit:20240308T160000
DTEND;TZID=America/Detroit:20240308T170000
SUMMARY:Workshop / Seminar:GEOMETRY SEMINAR:Applying diophantine conditions towards entropy and some number theoretical applications of the Einsiedler-Lindenstrauss theorem
DESCRIPTION:In the first part of the lecture\, Asaf will describe a measure classification result of Einsiedler-Fish\, showing how one can use diophantine conditions in order to achieve positive entropy for action of a polynomial non-lacunary semigroup on the one-torus. \nIn the second part\, Prasuna will discuss some applications of the Einsiedler-Lindenstrauss measure classification theorem in number theory.
UID:119582-21843037@events.umich.edu
URL:https://events.umich.edu/event/119582
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240306T095908
DTSTART;TZID=America/Detroit:20240311T150000
DTEND;TZID=America/Detroit:20240311T160000
SUMMARY:Workshop / Seminar:RTG NT: Families of CM forms
DESCRIPTION:Abstract: Given a Hecke character of a CM field\, the automorphic induction of which to the underlying totally real subfield gives a HIlbert modular form with complex multiplication. By the work of Hida and Tilouine the congruences of such forms are governed by the L-value associated with the Hecke character. On the other hand\, the Jacquet-Langlands lift of these modular forms to a quaternion algebra can be realized a the theta lift of the character to the corresponding unitary group. We will focus on the case when the unitary group is definite and discuss how one can p-integrally normalize the theta lift and the Rallis inner product formula. As a result we obtain a similar statement for the congruences. We will also discuss further arithmetic applications if time permits.
UID:117829-21840081@events.umich.edu
URL:https://events.umich.edu/event/117829
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240304T094401
DTSTART;TZID=America/Detroit:20240311T160000
DTEND;TZID=America/Detroit:20240311T170000
SUMMARY:Workshop / Seminar:Counting closed geodesics in the moduli space of Outer space: double exponential growth
DESCRIPTION:The problem of counting closed geodesics of bounded length\, originally in the setting of negatively curved manifolds\, goes back to the classic work of Margulis in 1960s about the dynamics of the geodesic flow. Since then Margulis' results have been generalized to many other contexts where some whiff of hyperbolicity is present.\nThus a 2011 result of Eskin and Mirzakhani shows that for a closed hyperbolic surface S of genus $g\ge 2$\, the number $N(L)$ of closed Teichmuller geodesics of length $\le L$ in the moduli space of $S$ grows as $e^{hL}/(hL)$ where $h=6g-6$. The number $N(L)$ is also equal to the number of conjugacy classes of pseudo-Anosov elements $\phi$ in the mapping class group $MCG(S)$ with $\log\lambda(\phi)\le L$\, where $\lambda(\phi)>1$ is the ``dilatation\" or ``stretch factor\" of $\phi$. \n\nWe consider an analogous problem in the $Out(F_r)$ setting\, for the action of the outer automorphism group $Out(F_r)$ of the free group $F_r$ of rank $r$ on a ``cousin\" of the Teichmuller space\, called the Culler-Vogtmann Outer space. In this context being a ``fully irreducible\" element of $Out(F_r)$ serves as a natural counterpart of being pseudo-Anosov. Every fully irreducible $\phi\in Out(F_r)$ acts on the Outer space as a loxodromic isometry with translation length $\log\lambda(\phi)$\, where again $\lambda(\phi)$ is the stretch factor of $\phi$. We estimate the number $N_r(L)$ of fully irreducible elements $\phi\in Out(F_r)$ with $\log\lambda(\phi)\le L$. The number $N_r(L)$ can also be interpreted as the number of homotopy classes of closed “contracting\" geodesics in the moduli space of the Outer space. We prove\, for $r\ge 3$\, that $N_r(L)$ grows \emph{doubly exponentially} in $L$ as $L\to\infty$\, in terms of both lower and upper bounds. This result reveals new behavior not present in classic hyperbolic dynamical systems. The talk is based on a joint paper with Catherine Pfaff.
UID:116377-21836671@events.umich.edu
URL:https://events.umich.edu/event/116377
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240305T103053
DTSTART;TZID=America/Detroit:20240311T160000
DTEND;TZID=America/Detroit:20240311T170000
SUMMARY:Workshop / Seminar:ISRMT seminar: Long-time Asymptotics of the KdV Steplike Solutions
DESCRIPTION:The long time asymptotics of the steplike solutions of the KdV equation on the constant backgrounds has long been well studied at the physical level of rigor. This talk will present some recent mathematically rigorous results that refine and justify the above-mentioned asymptotics. We will also compare the efficiency of the two most common methods --- the Nonlinear Steepest Descent and the Inverse Scattering Transform -- for obtaining the soliton asymptotics over a larger space-time domain and for the most general possible class of steplike initial data.
UID:118024-21840366@events.umich.edu
URL:https://events.umich.edu/event/118024
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - EH 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240310T164914
DTSTART;TZID=America/Detroit:20240311T160000
DTEND;TZID=America/Detroit:20240311T170000
SUMMARY:Workshop / Seminar:Student Combinatorics: An introduction to the m=1 amplituhedron
DESCRIPTION:Given a real (k+m) by n matrix Z\, there is an induced map from the TNN (k\,n)-Grassmannian to the (k\,k+m)-Grassmannian. The image of this map is called the amplituhedron A_{n\,k\,m}(Z). We will discuss some properties of this object when m=1. In particular\, we will see how to view the m=1 amplituhedron as a subcomplex of the TNN (k\,n)-Grassmannian and also as a complex of bounded faces of a hyperplane arrangement. \nReference: https://arxiv.org/abs/1608.08288
UID:119964-21843870@events.umich.edu
URL:https://events.umich.edu/event/119964
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Graduate Students
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240125T170252
DTSTART;TZID=America/Detroit:20240311T161500
DTEND;TZID=America/Detroit:20240311T173000
SUMMARY:Workshop / Seminar:GLNT
DESCRIPTION:TBA
UID:112530-21829084@events.umich.edu
URL:https://events.umich.edu/event/112530
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240221T075648
DTSTART;TZID=America/Detroit:20240312T150000
DTEND;TZID=America/Detroit:20240312T163000
SUMMARY:Lecture / Discussion:Functional MRI Speaker Series
DESCRIPTION:Title: Neural\, Performance and Trait Mechanisms of and Predictors in Mood Disorders\n\nAbstract: This talk will provide an overview of our work in rumination\, trauma\, and executive functioning in mood disorders. There will be a specific focus on putative mechanisms leading to risk for mood disorders\, exacerbation of or poor treatment response in mood disorders\, and predictors of treatment response and course in mood disorders. The work includes samples from early adulthood\, adolescence\, and late childhood.\n\n\n\n*Light refreshments will be served.\n*Please take the Church St. elevator to the 4th floor.
UID:118960-21841951@events.umich.edu
URL:https://events.umich.edu/event/118960
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Biosciences,Brain,Cognitive Neuroscience,Imaging,Neuroimaging,Neuropsychology,Neuroscience,Psychology
LOCATION:East Hall - 4464
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240310T203706
DTSTART;TZID=America/Detroit:20240312T150000
DTEND;TZID=America/Detroit:20240312T160000
SUMMARY:Workshop / Seminar:Student AIM Seminar: Continuous-Variable Quantum Simulation of Interacting Particle Systems
DESCRIPTION:Continuous-variable many-body systems with interactions involving quartic force fields (QFF) play a crucial role in modeling molecular vibrations and their interactions\, thereby serving as a bridge between quantum simulations and practical applications in spectroscopy. In this context\, the emerging field of continuous-variable quantum computation (CV-QC) offers a novel approach. CV-QC leverages continuous quantum information processing units (qumodes)\, mapping each continuous degree of freedom in the system being simulated onto a corresponding qumode of the quantum device. This paradigm presents a distinct contrast to digital quantum simulation methods\, such as the Zalka-Wiesner method\, which discretizes continuous-variable systems for simulation on digital quantum information platforms. In this talk\, we will explore the application of CV-QC to both quantum and classical many-body systems\, with a focus on systems described by QFFs and classical interacting particle systems.
UID:119969-21843875@events.umich.edu
URL:https://events.umich.edu/event/119969
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1068
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240206T082853
DTSTART;TZID=America/Detroit:20240312T160000
DTEND;TZID=America/Detroit:20240312T170000
SUMMARY:Workshop / Seminar:Colloquium Seminar: An introduction to rigid local systems
DESCRIPTION:A representation of a group G is said to be rigid\, if it cannot be continuously deformed to a non-isomorphic representation. If G happens to be the fundamental group of a complex projective manifold\, rigid representations are conjectured (by Carlos Simpson) to be of geometric origin. In this talk I will outline the basic properties of rigid local systems and discuss several consequences of Simpson‘s conjecture. I will then outline recent progress on these questions (joint work with Hélène Esnault) and briefly mention applications to geometry and number theory such as the recent resolution of the André-Oort conjecture by Pila-Shankar-Tsimerman.
UID:115386-21834608@events.umich.edu
URL:https://events.umich.edu/event/115386
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240311T230829
DTSTART;TZID=America/Detroit:20240312T160000
DTEND;TZID=America/Detroit:20240312T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: Computational versus Conceptual argumentation
DESCRIPTION:The debate on the validity of conceptual argumentation in mathematics can be traced at least as far back as 1850s Germany -- between computational Berlin-mathematicians like Kummer\, Kronecker and Weierstrass\, and conceptual Göttingen-mathematicians like Dirichlet\, Gauss\, and Riemann. This debate intensified with Hilbert's nonconstructive proof of the Basis Theorem leading to Gordan's famous quote: \"This is not Mathematics. This is Theology.\" This week's seminar addresses this debate from a History of Mathematics perspective\, with the goal of motivating the research program of reverse mathematics.
UID:120037-21843975@events.umich.edu
URL:https://events.umich.edu/event/120037
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240309T214607
DTSTART;TZID=America/Detroit:20240312T170000
DTEND;TZID=America/Detroit:20240312T180000
SUMMARY:Workshop / Seminar:Student Analysis Seminar: Power-law distribution in random graphs
DESCRIPTION:Heavy-tailed distributions for random variables have been studied extensively\, including\, for example\, in the study of random matrices\, in spin glass models in order to bridge the mean-field spin models and the more realistic ones with short-range interactions. In this talk\, we consider heavy-tailed distributions that are governed by a power law density. After covering definitions and several fundamental properties\, we will discuss a model for random graphs that was developed in an effort to explain the power law behavior observed in many complex networks in reality.
UID:119959-21843866@events.umich.edu
URL:https://events.umich.edu/event/119959
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240216T161326
DTSTART;TZID=America/Detroit:20240313T110000
DTEND;TZID=America/Detroit:20240313T120000
SUMMARY:Presentation:Interpolation of general affine groups in characteristic 0 via representation stability
DESCRIPTION:I will talk about an embedding of generic FI-modules into a non-semisimple pre-Tannakian category which interpolates the categories of representations of general affine groups which are iterated extensions of representations of general linear groups. I will also discuss an analogous interpolation of representations of semidirect products of symplectic groups with Heisenberg groups.
UID:117202-21838819@events.umich.edu
URL:https://events.umich.edu/event/117202
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240310T210255
DTSTART;TZID=America/Detroit:20240313T143000
DTEND;TZID=America/Detroit:20240313T160000
SUMMARY:Workshop / Seminar:Chow Group and Cohomology of Projective Simplicial Toric Varieties
DESCRIPTION:We will show that for projective simplicial toric varieties\, the Chow group is isomorphic to its cohomology\, thus showing various corollaries such as relating Betti numbers and the number of cones in the associated fan. Finally\, we will show a description of the cohomology ring in terms of generators and an ideal of relations.
UID:119970-21843876@events.umich.edu
URL:https://events.umich.edu/event/119970
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240309T111302
DTSTART;TZID=America/Detroit:20240313T150000
DTEND;TZID=America/Detroit:20240313T160000
SUMMARY:Workshop / Seminar:Student CA Seminar: Frobenius Splitting for Quotients of Regular Rings
DESCRIPTION:Any ring R of characteristic p > 0 is equipped with many natural endomorphisms: for e > 0\, the e-th Frobenius map is given by (F^e)(r) = r^(p^e). In this talk\, we'll study Hom_R(F^e_*R\, R): the R-module of splittings of this map. When R is a regular ring\, or more generally a Gorenstein ring\, this R-module can be canonically identified with F^e_*R itself. When S = R/I is a quotient of a regular ring\, the splittings of F^e: R/I -> R/I can be understood in terms of the ideal I. Using this framework\, we demonstrate criteria for determining whether a ring is F-split or F-regular.
UID:117319-21839165@events.umich.edu
URL:https://events.umich.edu/event/117319
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 1866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240308T104845
DTSTART;TZID=America/Detroit:20240313T150000
DTEND;TZID=America/Detroit:20240313T155000
SUMMARY:Workshop / Seminar:Student Number Theory: Motivating endoscopy via an example with SL(2)
DESCRIPTION:Endoscopy arises from the attempt to stabilize the trace formula. The \"stabilization\" of the trace formula is roughly speaking a procedure to make the trace formula more useful for applications and it is an extremely important tool in the Langlands program. I will attempt to motivate the role that endoscopy plays by gently walking through the stabilization of the elliptic regular part of the trace formula for SL(2). During our walkthrough\, we will see glimpses of the (elliptic) endoscopic groups\, transfer factors\, endoscopic transfer of functions\, cohomological invariants\, etc.—objects which all occur naturally in the theory of endoscopy.
UID:119884-21843732@events.umich.edu
URL:https://events.umich.edu/event/119884
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 5822
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240206T113041
DTSTART;TZID=America/Detroit:20240313T160000
DTEND;TZID=America/Detroit:20240313T173000
SUMMARY:Workshop / Seminar:Algebraic Geometry Seminar: p-adic integration and BPS cohomology
DESCRIPTION:I will report on joint work in progress with Wyss and Ziegler. The first part of this talk will be a gentle introduction to p-adic integration\, focusing on the case of quotient singularities where it is closely related to orbifold cohomology. In the second half we will compute p-adic integrals for singular moduli spaces of objects in certain abelian categories (e.g. representations of a symmetric quiver\, meromorphic Higgs bundles\, etc) and see that p-adic integration can be related to BPS cohomology arising in the theory of Donaldson-Thomas invariants.
UID:115384-21834606@events.umich.edu
URL:https://events.umich.edu/event/115384
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240202T161524
DTSTART;TZID=America/Detroit:20240313T160000
DTEND;TZID=America/Detroit:20240313T170000
SUMMARY:Workshop / Seminar:Generalization of Shapley's cooperative value allocation theory via random coalition process
DESCRIPTION:Lloyd Shapley’s cooperative value allocation theory is a central concept in game theory that is widely applied in various fields to assess individual contributions and allocate resources. The Shapley value formula and his four defining axioms form the foundation of the theory.\n\nWe interpret the Shapley value as an expectation of a certain stochastic path integral\, with each path representing a general coalition process. As a result\, the value allocation is naturally extended to all partial coalition states. Furthermore\, the new allocation scheme can be readily generalized by path-integrating various edge flows\, which we refer to as the f-Shapley value. Finally\, by employing Hodge theory on graphs\, we show how to compute the stochastic path integral via the graph Poisson equation.
UID:114233-21832531@events.umich.edu
URL:https://events.umich.edu/event/114233
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240308T210339
DTSTART;TZID=America/Detroit:20240313T160000
DTEND;TZID=America/Detroit:20240313T173000
SUMMARY:Workshop / Seminar:RTG GeomTopDyn
DESCRIPTION:TBA
UID:119952-21843859@events.umich.edu
URL:https://events.umich.edu/event/119952
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240311T095503
DTSTART;TZID=America/Detroit:20240313T160000
DTEND;TZID=America/Detroit:20240313T172000
SUMMARY:Workshop / Seminar:RTG GeomTopDyn Seminar. Diophantine applications of the Einsiedler-Lindenstrauss theorem
DESCRIPTION:We will discuss some applications of the Einsiedler-Lindenstrauss measure classification theorem in number theory.
UID:119979-21843891@events.umich.edu
URL:https://events.umich.edu/event/119979
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240311T011143
DTSTART;TZID=America/Detroit:20240314T160000
DTEND;TZID=America/Detroit:20240314T170000
SUMMARY:Workshop / Seminar:Commutative Algebra Seminar: Singularities of GL-varieties
DESCRIPTION:A GL-variety is a reduced affine scheme whose coordinate ring is a polynomial representation that is finitely generated up to the action of the infinite general linear group GL.\n\nEquivalently\, GL-varieties are inverse limits of Vec-varieties\, functors from the category of finite dimensional vector spaces to reduced affine varieties.\n\nIn a joint work with Jan Draisma and Christopher Chiu\, taking the perspective of Vec-varieties\, we show that the (inverse) limit of the singular loci of a Vec-variety evaluated in dimension n defines a closed Vec-subvariety of “singular points”.\n\nIn a forthcoming paper with Andrew Snowden\, we show that the GL-variety obtained from these \"singular points\" is actually the locus of singular points of the initial GL-variety\, namely\, the following loci coincide:\n\n1. The closed GL-variety arising from taking the limit of the singular points in the corresponding Vec-variety.\n2. The locus of points where the module of Kähler differential is not flat.\n3. The locus of points where the tangent space and tangent cone are not isomorphic.\n4. The locus of points that are not formally smooth.\n5. The locus of points where there is not an n_0 such that for all n> n_0 an n-jet lift to an n+1-jet.\n\nIn this talk\, I will present the necessary background and more details about the aforementioned results.
UID:119973-21843884@events.umich.edu
URL:https://events.umich.edu/event/119973
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - 3088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240308T102633
DTSTART;TZID=America/Detroit:20240314T160000
DTEND;TZID=America/Detroit:20240314T170000
SUMMARY:Workshop / Seminar:Differential Equations Seminar: Phase transition issue of focusing Gibbs measures for Schrödinger-wave systems
DESCRIPTION:We study the phase transition phenomenon of the singular Gibbs measure associated with the Schrödinger-wave systems\, initiated by Lebowitz\, Rose\, and Speer (1988). In the three-dimensional case\, this problem turns out to be critical\, exhibiting a phase transition according to the size of the coupling constant. In the weakly coupling region\, the Gibbs measure can be constructed as a probability measure\, which is singular with respect to the Gaussian free field. On the other hand\, in the strong coupling case\, the Gibbs measure can not be normalized as a probability measure. In particular\, the finite-dimensional truncated Gibbs measures have no weak limit\, even up to a subsequence.
UID:116183-21836395@events.umich.edu
URL:https://events.umich.edu/event/116183
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - EH4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240118T165126
DTSTART;TZID=America/Detroit:20240314T160000
DTEND;TZID=America/Detroit:20240314T173000
SUMMARY:Workshop / Seminar:Simplicial commutative rings
DESCRIPTION:TBA
UID:117418-21839278@events.umich.edu
URL:https://events.umich.edu/event/117418
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240310T230200
DTSTART;TZID=America/Detroit:20240314T160000
DTEND;TZID=America/Detroit:20240314T165000
SUMMARY:Workshop / Seminar:Student Dyn/Geo/Top: Heegaard Floer Homology and Unknotting Number
DESCRIPTION:Heegaard Floer homology is a powerful topological invariant of\n3-manifolds and knots. The unknotting number is an invariant of knots\nthat is easy to define but can be difficult to compute. In this talk\,\nI will review some results that show how Heegaard Floer homology has\nbeen used to determine unknotting numbers of certain knots.
UID:119971-21843877@events.umich.edu
URL:https://events.umich.edu/event/119971
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar,Talk
LOCATION:East Hall - 2866
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240304T095117
DTSTART;TZID=America/Detroit:20240315T150000
DTEND;TZID=America/Detroit:20240315T160000
SUMMARY:Lecture / Discussion:AIM Seminar: A boundary integral equation method for superhydrophobic flow
DESCRIPTION:Abstract: We present the development of a fast and accurate boundary integral equation (BIE) method for the computation of two-dimensional incompressible Stokes flow over superhydrophobic (SH) surfaces. These surfaces are composed of alternating solid portions\, grooves\, or air pockets\, leading to enhanced slip\, and are particularly relevant for microfluidic device design. While BIE methods offer advantages in SH flow computations\, problems involving SH surfaces present challenges due to flow singularities resulting from complex surface microstructures. These challenges include mixed boundary conditions and geometric corners\, causing standard quadrature rules for smooth integrals to suffer from severe accuracy loss. Although often used adaptive mesh refinement can mitigate this issue\, it tends to grow the size of discretization significantly\, and has difficulties in achieving satisfactory accuracy due to linear system ill-conditioning. To resolve these issues\, we combine the Recursively Compressed Inverse Preconditioning (RCIP) method with a scaling technique\, kernel-split quadratures\, and the Fast Multipole Method. This incorporation yields a fast and accurate numerical scheme for SH flow computations. We demonstrate the effectiveness of our method through several illustrative examples. This research is joint work with Shidong Jiang (Flatiron Institute) and Michael Siegel (New Jersey Institute of Technology).\n\nContact: Robert Krasny
UID:114768-21833583@events.umich.edu
URL:https://events.umich.edu/event/114768
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1084
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240312T090517
DTSTART;TZID=America/Detroit:20240315T150000
DTEND;TZID=America/Detroit:20240315T160000
SUMMARY:Workshop / Seminar:Discrete Morse Theory for Symmetric Delta-complexes
DESCRIPTION:In this talk\, we generalize discrete Morse theory to the context of symmetric Delta-complexes. First introduced by Forman\, discrete Morse theory is an adaptation of Morse theory for regular CW-complexes. It gives a schematic for collapsing cells in a CW-complex while maintaining the same homotopy type. On the other hand\, symmetric Delta-complexes are a generalization of cell-complexes. They are topological spaces built from quotients of standard simplices\, and they have played important roles in recent developments of tropical geometry. We generalize various concepts from discrete Morse theory\, including discrete Morse functions and acyclic matchings on face posets\, and prove parallel theorems for symmetric Delta-complexes. We also apply this new theory to the moduli space of tropical abelian varieties.
UID:119032-21842058@events.umich.edu
URL:https://events.umich.edu/event/119032
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240310T175213
DTSTART;TZID=America/Detroit:20240315T150000
DTEND;TZID=America/Detroit:20240315T160000
SUMMARY:Workshop / Seminar:The Beauville decomposition
DESCRIPTION:Mukai's seminal work proved that the \"convolution\" with the Poincaré line bundle induces an equivalence of the derived categories of an abelian variety and its dual variety. This equivalence specializes to rational Chow groups of these varieties are isomorphic. We will exploit this structure to exhibit that the rational Chow ring of an abelian variety has an interesting decomposition called the Beauville decomposition.
UID:119965-21843871@events.umich.edu
URL:https://events.umich.edu/event/119965
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4088
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240311T103736
DTSTART;TZID=America/Detroit:20240315T160000
DTEND;TZID=America/Detroit:20240315T173000
SUMMARY:Lecture / Discussion:Linguistics Colloquium
DESCRIPTION:Jessi Grieser is an Associate Professor in the Department of Linguistics at the University of Michigan. Her research focuses on the use of African American Language style in the creation and maintenance of identities which are not necessarily ethnoracial in nature\, particularly identities of place and class\, with healthy side servings of geosemiotics and the study of language online. Jessi works using the methods of discourse analysis\, sociophonetics\, and quantitative variationist analysis\, and especially the intersections thereof. \n\nTITLE\nThe Art of Invention\n\nABSTRACT \nThis talk addresses one of the thorniest questions facing new graduate students: where do I get good ideas and how do I develop them in useful ways? Using my own career as a case study\, I'll talk about successes and failures\, and unexpected detours and I'll demonstrate 7 techniques of idea generation which have shaped my work. We'll also talk about what it means to get a Ph.D. more generally and I'll give five tips about how to interact with your work and others in ways that produce scholarly output\, can make the process of becoming a Ph.D. straightforward and perhaps\, even fun. \n\nJoin us in person or virtually
UID:119694-21843417@events.umich.edu
URL:https://events.umich.edu/event/119694
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Free
LOCATION:East Hall - 4448
CONTACT:
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240309T133755
DTSTART;TZID=America/Detroit:20240315T160000
DTEND;TZID=America/Detroit:20240315T170000
SUMMARY:Presentation:Twisted rabbit problems in higher degree
DESCRIPTION:In the 1980s Hubbard proposed a compelling question: when composing a polynomial known as the rabbit polynomial with a homeomorphism\, the resulting map is equivalent to another (possibly different) polynomial. This question remained open for 25 years until Bartholdi–Nekrashevych solved in in 2006. In this talk\, I highlight work with Mukundan and with Lanier that uses the combinatorial topological algorithm developed with Belk\, Lanier\, and Margalit to solve higher degree analogues of Hubbard's twisted rabbit problem. Our solutions reveal structure within unicritical degree-d polynomials in which the critical point is periodic and introduce accessible questions. This is a joint meeting of the dynamics seminar + the geometry seminar.
UID:117193-21838808@events.umich.edu
URL:https://events.umich.edu/event/117193
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3866
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240309T134414
DTSTART;TZID=America/Detroit:20240318T160000
DTEND;TZID=America/Detroit:20240318T170000
SUMMARY:Presentation:Connectedness of moduli spaces: From plane curves to rational maps
DESCRIPTION:In this talk we describe some ways that fundamental groups and other topological notions have been applied to determine connectedness of moduli spaces. In the 1930s Zariski studied the question of whether the moduli space of plane curves of fixed degree with a certain set of prescribed singularities is connected. He famously showed that plane sextic curves with six cusps and no other singularities is disconnected: the two components corresponding to whether the cusps or not the cusps are in general position or lie on a conic. To prove this\, Zariski developed and used tools around fundamental groups and branched coverings\, showing that purely topological data can be used to answer geometric questions: the deformability of six cuspidal sextics one to the other. Recently\, Milnor asked an analogous question in the realm of rational maps: Is the moduli space of quadratic rational maps of a fixed degree and a prescribed orbit portrait for one of the critical points connected? This problem is still wide open. In this talk we will describe some partial results with a particular focus on the use of topological techniques a la Zariski in this context.
UID:116805-21838049@events.umich.edu
URL:https://events.umich.edu/event/116805
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3096
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240316T144053
DTSTART;TZID=America/Detroit:20240318T160000
DTEND;TZID=America/Detroit:20240318T160000
SUMMARY:Workshop / Seminar:Student Combinatorics: A Geometric Perspective on the q\,t-Catalan Numbers
DESCRIPTION:Dyck paths are combinatorial objects enumerated by the Catalan numbers. We can write a generating function for Dyck paths\, using q to keep track of the area statistic\, and t to keep track of the bounce statistic. Amazingly\, while this function is symmetric in q and t\, a bijection on Dyck paths that swaps area and bounce continues to elude even the most tenacious combinatistas. Recent work of Guoce Xin and Yingrui Zhang suggests promising results from studying a generalization of Dyck paths. Drawing inspiration from this work\, we will discuss how to view Dyck paths as integer points of cones\, hoping that the geometric perspective will shed new light on this problem. This is joint work with Matthias Beck\, Mitsuki Hanada\, Max Hlavacek\, John Lentfer\, and Andrés Vindas Meléndez.
UID:120252-21844473@events.umich.edu
URL:https://events.umich.edu/event/120252
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Graduate Students
LOCATION:East Hall - 3866
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240317T153906
DTSTART;TZID=America/Detroit:20240318T161500
DTEND;TZID=America/Detroit:20240318T171500
SUMMARY:Workshop / Seminar:GLNT: Derived cycles on Shimura varieties and p-adic methods
DESCRIPTION:Abstract: A series of conjectures of Steve Kudla\, following classical work of Hirzerbuch-Zagier\, Gross-Zagier and Gross-Kohnen-Zagier\, predicts that (arithmetic) special cycle classes on certain Shimura varieties can be viewed as Fourier coefficients of automorphic forms in a suitable sense. There is a difficulty even in the formulation of the problem\, because the 'natural' definition of cycles associated with degenerate coefficients yields cycles in the wrong degree\, an issue that gets rather more severe when one tries to work over the integral model. I'll explain how the theory of virtual fundamental classes for certain derived complete intersection maps gives a systematic fix for this issue\, and how recent developments in integral p-adic Hodge theory (joint w. Mathew and Gardner) help to construct such maps.
UID:112531-21829085@events.umich.edu
URL:https://events.umich.edu/event/112531
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 3088
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240317T201243
DTSTART;TZID=America/Detroit:20240319T150000
DTEND;TZID=America/Detroit:20240319T160000
SUMMARY:Workshop / Seminar:Student AIM Seminar: Non-parametric estimates for graphon mean-field particle systems
DESCRIPTION:Abstract: We consider the graphon mean-field system introduced in the work of Bayraktar\, Chakraborty\, and Wu. It is the large-population limit of a heterogeneously interacting diffusive particle system\, where the interaction is of mean-field type with weights characterized by an underlying graphon function. Through observation of continuous-time trajectories within the particle system\, we construct plug-in estimators of the particle density\, the drift coefficient\, and thus the graphon interaction weights of the mean-field system. Our estimators for the density and drift are direct results of kernel interpolation on the empirical data\, and a deconvolution method leads to an estimator of the underlying graphon function. We show that\, as the number of particles increases\, the graphon estimator converges to the true graphon function pointwisely\, and as a consequence\, in the cut metric. Besides\, we conduct a minimax analysis within a particular class of particle systems to justify the pointwise optimality of the density and drift estimators.
UID:120266-21844488@events.umich.edu
URL:https://events.umich.edu/event/120266
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1068
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240305T110536
DTSTART;TZID=America/Detroit:20240319T160000
DTEND;TZID=America/Detroit:20240319T170000
SUMMARY:Lecture / Discussion:Math Undergraduate Seminar: Bombieri-Vinogradov Theorem
DESCRIPTION:In this talk\, we sketch a proof of the famous Bombieri-Vinogradov theorem and some of the implications.
UID:119698-21843421@events.umich.edu
URL:https://events.umich.edu/event/119698
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,Talk,Undergraduate Students
LOCATION:East Hall - B743
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240315T100531
DTSTART;TZID=America/Detroit:20240319T160000
DTEND;TZID=America/Detroit:20240319T170000
SUMMARY:Workshop / Seminar:Sumner Myers Colloqium: Parabolic Towers and the Asymptotic Geometry of the Mandelbrot set
DESCRIPTION:Understanding the geometry of the Mandelbrot set has been a central pillar of holomorphic dynamics over the past four decades. Much of its structure is now understood\, but a critical question remains unresolved: is the Mandelbrot set locally connected? The first major breakthrough towards this conjecture was achieved by Yoccoz in the nineties\, who proved that the Mandelbrot set is locally connected at all parameters which are not infinitely quadratic-like renormalizable. A key ingredient in Yoccoz’s work is the PLY-inequality\, which bounds the diameter of certain subsets\, called limbs\, of the Mandelbrot set. These limbs are naturally labeled by the rational numbers\, and the PLY-inequality asserts that the p/q-limb of the Mandelbrot set has size O(1/q). Milnor conjectured that O(1/q2) is the correct scale. For any N ≥ 1\, the main result of this thesis is to verify Milnor’s conjecture for all p/q-limbs where a finite continued fraction of p/q has uniformly bounded length. Our strategy relies on careful analysis of the bifurcation of parabolic fixed points\; we also further develop some of the classical theory in this area. We introduce parabolic and near-parabolic renormalization operators for maps which have parabolic fixed points of arbitrary multiplier and there perturbations\, constructing invariant classes for these operators. We provide an alternative definition to the parabolic towers introduced by Epstein and construct a dynamically natural topology on the space of all parabolic towers. We also study the dynamics of Lavaurs maps\, constructing analogues of polynomial external rays for these functions showing that these rays arise as the Hausdorff limits of polynomial external rays.
UID:120208-21844223@events.umich.edu
URL:https://events.umich.edu/event/120208
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1360
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240316T231651
DTSTART;TZID=America/Detroit:20240319T170000
DTEND;TZID=America/Detroit:20240319T180000
SUMMARY:Workshop / Seminar:Student Analysis Seminar: Counting Problems & Wave Kinetic Theory
DESCRIPTION:In this talk\, we will learn about Wave Kinetic Theory through the lens of the Cubic Nonlinear Schrodinger Equation. We will begin with an overview of the Wave Kinetic Equation and then talk about how one could prove that it holds. One of the major aspects of proofs used to establish Kinetic Theory is that the problem can be reduced to a counting problem of certain types of mathematical trees/molecules. We focus on the main steps of this reduction and the challenges we may encounter in the counting problem.
UID:120256-21844477@events.umich.edu
URL:https://events.umich.edu/event/120256
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 4096
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240317T180104
DTSTART;TZID=America/Detroit:20240320T110000
DTEND;TZID=America/Detroit:20240320T120000
SUMMARY:Presentation:Low rank symmetric fusion categories in positive characteristic
DESCRIPTION:In this talk\, we look at the classification problem for symmetric fusion categories in positive characteristic. We recall the second Adams operation on the Grothendieck ring and use its properties to obtain some classification results. In particular\, we show that the Adams operation is not the identity for any non-trivial symmetric fusion category. We also give lower bounds for the rank of a (non-super-Tannakian) symmetric fusion category in terms of the characteristic of the field. As an application of these results\, we classify all symmetric fusion categories of rank 3 and those of rank 4 with exactly two self-dual simple objects.
UID:117203-21838820@events.umich.edu
URL:https://events.umich.edu/event/117203
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics,seminar
LOCATION:East Hall - Pillsbury Room
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240317T122934
DTSTART;TZID=America/Detroit:20240320T143000
DTEND;TZID=America/Detroit:20240320T160000
SUMMARY:Workshop / Seminar:Learning Seminar in Algebraic Combinatorics: Examples with combinatorial Chow rings
DESCRIPTION:In this learning seminar\, we have been converting questions about face counts of polytopes into questions about the cohomology of toric varieties. In the case of toric varieties associated to a (nice enough) fan\, the cohomology is isomorphic to a combinatorial Chow ring. As their name suggests\, the generators and relations of these rings can be described directly from the combinatorics of the fan. We will describe these rings\, and give several detailed examples.
UID:120261-21844482@events.umich.edu
URL:https://events.umich.edu/event/120261
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:
LOCATION:East Hall - 4088
CONTACT:
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BEGIN:VEVENT
DTSTAMP:20240317T080502
DTSTART;TZID=America/Detroit:20240320T150000
DTEND;TZID=America/Detroit:20240320T160000
SUMMARY:Workshop / Seminar:Student CA Seminar - Progress in Big and Small Cohen-Macaulay Modules
DESCRIPTION:Given a Noetherian local ring (R\,m)\, one might ask whether there exists an R-module M and a system of parameters on R which form a regular sequence on M. Furthermore one might ask whether such M can be chosen to be finitely generated. Modules M satisfying these properties are called Big and Small Cohen-Macaulay modules\, respectively. This talk gives a brief historical overview of progress on two major conjectures regarding the existence of Big and Small Cohen-Macaulay Modules.
UID:120259-21844480@events.umich.edu
URL:https://events.umich.edu/event/120259
CLASS:PUBLIC
STATUS:CONFIRMED
CATEGORIES:Mathematics
LOCATION:East Hall - 1866
CONTACT:
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END:VCALENDAR