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VERSION:2.0
PRODID:Mathematics Seminar Calendar
BEGIN:VEVENT
UID:20191214T162846-18593@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Probing 4-manifolds with near-symplectic forms
DESCRIPTION:Speaker\: Chris Gerig, Harvard University \r\nMost closed 4-manifolds do not admit symplectic forms, but most admit "near-symplectic forms", certain closed 2-forms which are symplectic outside of a collection of circles. This provides a gateway from the symplectic world to the non-symplectic world. I will first briefly sketch a geometric interpretation of the Seiberg-Witten invariants in terms of J-holomorphic curves that are compatible with the near-symplectic form. Although the Seiberg-Witten invariants don't apply to (potentially exotic) 4-spheres, nor do these spheres admit near-symplectic forms, there is still a way to bring in near-symplectic techniques.
LOCATION:C304 Wells Hall
DTSTART:20190829T180000Z
DTEND:20190829T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18593
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19616@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Organizational meeting
DESCRIPTION:Speaker\: \r\n
LOCATION:C304 Wells Hall
DTSTART:20190903T160000Z
DTEND:20190903T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19616
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19605@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:An introduction to q-analogues
DESCRIPTION:Speaker\: Bruce Sagan, MSU\r\nThe theory of q-analogues is important in both combinatorics and the study of hypergeometric series. Roughly speaking, the q-analogue of a mathematical object (which could be a number or a theorem or ...) is another object depending on a parameter q which reduces to the original object when q=1. This talk will be a gentle introduction to q-analogues. No background will be assumed.
LOCATION:C304 Wells Hall
DTSTART:20190904T190000Z
DTEND:20190904T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19605
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19603@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Proof of average-case #P- hardness of random circuit sampling with some robustness, and a protocol for blind quantum computation
DESCRIPTION:Speaker\: Ramis Movassagh, IBM\r\nA one-parameter unitary-valued interpolation between any two unitary matrices (e.g., quantum gates) is constructed based on the Cayley transformation. We prove that this path induces probability measures that are arbitrarily close to the Haar measure and prove the simplest known average-case # P -hardness of random circuit sampling (RCS). RCS is the task of sampling from the output distribution of a quantum circuit whose local gates are random Haar unitaries, and is the lead candidate for demonstrating quantum supremacy in the "noisy intermediate scale quantum (NISQ)" computing era. Here we also prove exp(-Θ(n^4 )) robustness with respect to additive error. This overcomes issues that arise for extrapolations based on the truncations of the power series representation of the exponential function. (Dis)Proving the quantum supremacy conjecture requires an extension of this analysis to noise that is polynomially small in the system's size. This remains an open problem. Lastly, an efficient and private protocol for blind quantum computation is proposed that uses the Cayley deformations proposed herein for encryption. This is an efficient protocol that only requires classical communication between Alice and Bob.\r\n** The talk is self-contained and does not require any pre-req beyond basic linear algebra (e.g, knowing what a unitary matrix is).\r\n
LOCATION:C304 Wells Hall
DTSTART:20190905T150000Z
DTEND:20190905T160000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19603
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19602@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:$G_2$-instantons on the 7-sphere
DESCRIPTION:Speaker\: Alex Waldron, Michigan State University \r\nI'll discuss a forthcoming paper studying families of $G_2$-instantons on $S^7$, focusing on those which are obtained by pulling back asd instantons on $S^4 $ via the quaternionic Hopf fibration. In the charge-1 case this yields a smooth and complete 15-dimensional family. The situation for higher charge is more complicated, but we are able to compute all the infinitesimal deformations.
LOCATION:C304 Wells Hall
DTSTART:20190905T180000Z
DTEND:20190905T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19602
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19615@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Localization of Gaussian disordered systems at low temperature
DESCRIPTION:Speaker\: Erik Bates, UC Berkeley\r\nThe fundamental premise of statistical mechanics is that a physical system's state is random according to some probability measure, which is determined by the various forces of interaction between the system's constituent particles. In the ``disordered" setting, these interactions are also random (meant to capture the effect of a random medium), meaning the probability measure is itself a random object. This setting includes several of the models most widely studied by mathematical physicists, such as the Random Energy Model, the Sherrington--Kirkpatrick spin glass, and directed polymers. The most intriguing part of their phase diagrams occurs at low temperature, when the measure concentrates, or "freezes", on energetically favorable states. In general, quantifying this phenomenon is especially challenging, in large part due to the extra layer of randomness created by the disorder. This talk will describe recent progress on this question, leading us to some conjectures on further open problems. (Joint work with Sourav Chatterjee)
LOCATION:C405 Wells Hall
DTSTART:20190905T190000Z
DTEND:20190905T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19615
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18596@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Applications of Constructible Sheaves to Symplectic Topology
DESCRIPTION:Speaker\: Eric Zaslow, Northwestern University\r\nMy goal is to explain a few applications of constructible sheaves to symplectic topology through examples that we can calculate together on the board.\r\n\r\nIn particular, I would like to explain how sheaves relate to: 1) Legendrian knot invariants, 2) cluster varieties, 3) nonfillability results for Legendrian surfaces.
LOCATION:C304 Wells Hall
DTSTART:20190905T201000Z
DTEND:20190905T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18596
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19623@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Potluck and introduction
DESCRIPTION:Speaker\: AMS Student Chapter, MSU\r\nCome learn what AMS is all about, what events are scheduled for this year, and meet your student community! This event is for ALL members, new and returning.\r\n\r\nWe'd love it if you could bring a snack or dish to share if you're able to. \r\n\r\nWe are also looking to fill two eboard positions: secretary and treasurer! We will discuss more about these positions on Tuesday and would love to hear from you if you're interested.
LOCATION:C204 Wells Hall
DTSTART:20190909T200000Z
DTEND:20190909T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19623
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19620@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Accommodations for students with RCPD VISAs
DESCRIPTION:Speaker\: Rachael Lund + Andy Krause, MSU\r\nWe talk as a group about how we are appropriately accommodating students with VISAs, with a specific emphasis on groupwork-exempt accommodations.
LOCATION:C109 Wells Hall
DTSTART:20190909T201000Z
DTEND:20190909T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19620
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19613@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Gröbner basis and the Ideal Membership problem
DESCRIPTION:Speaker\: Ioannis Zachos, Michigan State\r\nWe know from the Hilbert Basis Theorem that any ideal in a polynomial ring over a field is finitely generated. However, there remains question as to the best generators to choose to describe the ideal. Are there generators for a polynomial ideal $I$ that make it easy to see if a given polynomial $f$ belongs to $I$? For instance, does $2x^2z^2+2xyz^2+2xz^3+z^3-1$ belong to $I=(x+y+z, xy+xz+yz, xyz−1)$? Deciding if a polynomial is in an ideal is called the Ideal Membership Problem. In polynomial rings of one variable, we use long division of polynomials to solve this problem. There is a corresponding algorithm for $K[x_1,\ldots, x_n]$, but because there are multiple variables and multiple divisors, the remainder of the division is not unique. Hence a remainder of $0$ is a sufficient condition, but not a necessary condition, to determine ideal membership. However, if we choose the correct divisors, then the remainder is unique regardless of the order of the divisors. These divisors are called a Gröbner basis. In our talk we will define the Gröbner basis and see how it solves the Ideal Membership Problem.
LOCATION:C304 Wells Hall
DTSTART:20190909T203000Z
DTEND:20190909T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19613
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19617@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Introduction to Free Products of von Neumann Algebras
DESCRIPTION:Speaker\: Brent Nelson, MSU\r\nIn this learning seminar, I will give an introduction to the free product construction for von Neumann algebras, which is the direct analogue of a free product for groups. Moreover, it defines the non-commutative independence relation most frequently used in free probability. No prior knowledge of von Neumann algebras will be necessary.
LOCATION:C304 Wells Hall
DTSTART:20190910T150000Z
DTEND:20190910T160000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19617
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19624@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Combinatorial interpretations of Lucas analogues
DESCRIPTION:Speaker\: Bruce Sagan, MSU\r\nThe Lucas sequence is a sequence of polynomials in $s,t$ defined recursively by $\{0\}=0$, $\{1\}=1$, and $\{n\}=s\{n-1\}+t\{n-2\}$ for $n\ge2$. On specialization of $s$ and $t$ one can recover the Fibonacci numbers, the nonnegative integers, and the $q$-integers $[n]_q$. Given a quantity which is expressed in terms of products and quotients of nonnegative integers, one obtains a Lucas analogue by replacing each factor of $n$ in the expression with $\{n\}$. It is then natural to ask if the resulting rational function is actually a polynomial in $s$ and $t$ and, if so, what it counts. Using lattice paths, we give combinatorial models for Lucas analogues of binomial coefficients. We also consider Catalan numbers and their relatives, such as those for finite Coxeter groups. This is joint work with Curtis Bennett, Juan Carrillo, and John Machacek.
LOCATION:C304 Wells Hall
DTSTART:20190911T190000Z
DTEND:20190911T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19624
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-17489@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Rough solutions to the three-dimensional compressible Euler equations with vorticity and entropy
DESCRIPTION:Speaker\: Marcelo Disconzi, Vanderbilt University\r\nWe prove a series of intimately related results tied to the regularity and geometry of solutions to the three-dimensional compressible Euler equations.\r\n\r\nThe solutions are allowed to have nontrivial vorticity and entropy, and an arbitrary equation of state with positive sound speed. The central theme is that under low regularity assumptions on the initial data, it is possible to avoid, at least for short times, the formation of shocks. Our main result is that the time of classical existence can be controlled under low regularity assumptions on the part of the initial data associated with propagation of sound waves in the fluid. Such low regularity assumptions are in fact optimal. To implement our approach, we derive several results of independent interest: (i) sharp estimates for the acoustic geometry, which in particular capture how the vorticity and entropy interact with the sound waves; (ii) Strichartz estimates for quasilinear sound waves coupled to vorticity and entropy; (iii) Schauder estimates for the transport-div-curl-part of the systems. Compared to previous works on low regularity, the main new feature of our result is that the quasilinear PDE system under study exhibit multiple speeds of propagation. In fact, this is the first result of its kind for a system with multiple characteristic speeds. An interesting feature of our proof is the use of techniques that originated in the study of the vacuum Einstein equations in general relativity.
LOCATION:C304 Wells Hall
DTSTART:20190911T201000Z
DTEND:20190911T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=17489
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19606@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Free products of finite-dimensional von Neumann algebras
DESCRIPTION:Speaker\: Mike Hartglass, Santa Clara University\r\nI will present joint work with Brent Nelson, where we classify the structure of free products of von Neumann algebras equipped with arbitrary states. Our techniques use our other joint work of assigning a von Neumann algebra associated to a weighted graph. I will discuss this work and how it leads to computing finite-dimensional free products.
LOCATION:C304 Wells Hall
DTSTART:20190912T150000Z
DTEND:20190912T160000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19606
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19635@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Augmentations and sheaves for links
DESCRIPTION:Speaker\: Honghao Gao, MSU\r\nWe study two different invariants of framed oriented links. Augmentations are rank one representations of a non-commutative algebra, whose definition is motivated by Floer homology. Sheaves in microlocal theory can be thought of as generalizations of link group representations. We will demonstrate two constructions going back and forth between these invariants. We will also tell a motivating story behind the scene, using SFT and microlocalization correspondence in symplectic topology.
LOCATION:C304 Wells Hall
DTSTART:20190912T180000Z
DTEND:20190912T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19635
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19625@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Developing Finite Element Solvers for Poroelasticity in the Two-field Approach
DESCRIPTION:Speaker\: Jiangguo (James) Liu, Colorado State University\r\nThis talk presents results from our recent efforts for reviving the 2-field approach (fluid pressure and solid displacement) for numerically solving poroelasticity problems. We choose quadrilateral and hexahedral meshes for spatial discretization since they are equally flexible in accommodating complicated domain geometry but involve less unknowns, compared to simplicial meshes. The Darcy equation is solved for fluid pressure by the novel weak Galerkin finite element methods, which establish the discrete weak gradient and numerical velocity in the Arbogast-Correa spaces. The elasticity equation is solved for solid displacement by the enriched Lagrangian elements, which were motivated by the Bernardi-Raugel elements for Stokes flow. These two types of finite elements are coupled through the implicit Euler temporal discretization to solve poroelasticity. Numerical experiments on benchmarks will be presented to show that the new solvers are locking-free. Implementation on deal.II will be discussed also. This talk is based on a series of joint work with several collaborators.
LOCATION:C304 Wells Hall
DTSTART:20190913T201000Z
DTEND:20190913T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19625
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19610@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:P.D. rings with a view towards Crystals
DESCRIPTION:Speaker\: Chuangtian Guan, MSU\r\nIn this talk we will define P.D. rings, which are triples consisting a ring, an ideal of the ring and a map on an ideal mimicking $x^n/n!$. We will give some examples of P.D. rings and discuss their properties. Then we will use the P.D. structures to define the crystalline site of schemes and crystals. If time admits we will talk about some examples of crystals and explain why we care about them.
LOCATION:C304 Wells Hall
DTSTART:20190916T203000Z
DTEND:20190916T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19610
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19634@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Morse homology
DESCRIPTION:Speaker\: Dongsoo Lee, MSU\r\nFirst meeting of seminar on instanton Floer homology.
LOCATION:C304 Wells Hall
DTSTART:20190917T160000Z
DTEND:20190917T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19634
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19636@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Legendrian knots and augmentation varieties
DESCRIPTION:Speaker\: Honghao Gao, MSU\r\nWe begin with a gentle introduction to Legendrian knot and its invariant theory. We will define the Chekanov-Eliashberg different graded algebra and augmentations associated to the dga. We also present an example where the augmentation variety is a cluster variety.
LOCATION:C204A Wells Hall
DTSTART:20190917T190000Z
DTEND:20190917T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19636
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19642@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Perfectoid Fields and Tilting
DESCRIPTION:Speaker\: Nick Rekuski, MSU\r\nIn this talk we will introduce perfectoid fields and tilting. Perfectoid fields provide the the correct base scheme for perfectoid spaces. Tilting is a fundamental tool that will let us lift characteristic $0$ results to characteristic $p$ results. For example, if $K$ is a characteristic $0$ perfectoid field and $K^{\flat}$ is a tilt of $K$ then $K^{\flat}$ is a characteristic $p$ field; $K^{\circ}/K^{\circ\circ}\cong K^{\flat \circ}/K^{\flat\circ\circ}$; if $[L:K]$ is finite then $[L^{\flat}:K^{\flat}]=[L:K]$ (in particular, $L$ is perfectoid); and there is an equivalence of categories between finite étale covers of $K$ and finite étale covers of $K^{\flat}$ via $L\mapsto L^{\flat}$.\r\n\r\nThis talk will not require any material beyond first-year graduate algebra. However, the sophistication required may be higher. To make this talk as accessible as possible, we will include numerous examples.
LOCATION:C329 Wells Hall
DTSTART:20190919T140000Z
DTEND:20190919T153000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19642
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19607@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Tracial stability and related topics in operator algebras
DESCRIPTION:Speaker\: Scott Atkinson, University of California, Riverside\r\nWe will discuss the notion of tracial stability for operator algebras. Morally, an algebra A is tracially stable if approximate homomorphisms on A are near honest homomorphisms on A. We will discuss several examples and non-examples of tracially stable algebras including certain graph products (simultaneous generalization of free and tensor products) of C*-algebras. We will also discuss properties closely related to tracial stability that provide new characterizations of amenability. Parts of this talk are based on joint work with Srivatsav Kunnawalkam Elayavalli.
LOCATION:C304 Wells Hall
DTSTART:20190919T153000Z
DTEND:20190919T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19607
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18587@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Introduction to the Energy Identity for Yang-Mills
DESCRIPTION:Speaker\: Aaron Naber, Northwestern University\r\nIn this talk we give an introduction to the analysis of the Yang-Mills equation in higher dimensions. In particular, when studying sequences of solutions we will study the manner in which blow up can occur, and how this blow up may be understood through the classical notions of the defect measure and bubbles. The energy identity is an explicit conjectural relationship relating the energy density of the defect measure at a point to the bubbles which occur at that point. This talk is introductory and we will spend most of our time understanding the words of this abstract. If time permits we will briefly discuss the ideas needed to prove this conjecture and the related $W^{2,1}$-conjecture. The work is joint with Daniele Valtorta.
LOCATION:C304 Wells Hall
DTSTART:20190919T201000Z
DTEND:20190919T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18587
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19637@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Special event: Introductions to Ongoing Undergraduate MTH and STT Research Projects
DESCRIPTION:Speaker\: Jeanne Wald, MSU\r\nExchange and MSU Student Research Teams will give brief introductions to their research projects.
LOCATION:C304 Wells Hall
DTSTART:20190920T201000Z
DTEND:20190920T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19637
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19631@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Splitting Criteria for Vector Bundles on $\mathbb{P}^n$
DESCRIPTION:Speaker\: Nick Rekuski, Michigan State\r\nGrothendieck's Theorem says that any vector bundle on $\mathbb{P}^1$ can be decomposed as a finite sum of line bundles. In this talk, we will discuss a generalization of this theorem: Horrocks Splitting Criterion. This criterion completely describes when a vector bundle on $\mathbb{P}^n$ splits as a sum of line bundles. We will then discuss an open conjecture of Hartshorne. If time permits, we will also consider the similar question of classifying when a vector bundle on $\mathbb{P}^n$ decompose as line bundles and twists of the tangent bundle.
LOCATION:C304 Wells Hall
DTSTART:20190923T203000Z
DTEND:20190923T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19631
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19651@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:More on Morse homology
DESCRIPTION:Speaker\: Honghao Gao, MSU\r\n
LOCATION:C117 Wells Hall
DTSTART:20190924T160000Z
DTEND:20190924T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19651
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19647@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Legendrian knots and augmentation varieties
DESCRIPTION:Speaker\: Honghao Gao, MSU\r\nWe begin with a gentle introduction to Legendrian knot and its invariant theory. We will define the Chekanov-Eliashberg different graded algebra and augmentations associated to the dga. We also present an example where the augmentation variety is a cluster variety.
LOCATION:C204A Wells Hall
DTSTART:20190924T190000Z
DTEND:20190924T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19647
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19644@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Lucas atoms
DESCRIPTION:Speaker\: Bruce Sagan, MSU\r\n We introduce a powerful algebraic method for proving that Lucas analogues are polynomials with nonnegative coefficients. In particular, we factor a Lucas polynomial as\r\n$\{n\}=\prod_{d|n} P_d(s,t)$, where we call the polynomials $P_d(s,t)$ Lucas atoms. \r\nThis permits us to show that the Lucas analogues of the Fuss-Catalan and Fuss-Narayana numbers for all irreducible Coxeter groups are polynomials in $s,t$.\r\nUsing gamma expansions, a technique which has recently become popular in combinatorics and geometry, one can show that the Lucas atoms have a close relationship with cyclotomic polynomials $\Phi_d(q)$. \r\nCertain results about the $\Phi_d(q)$ can then be lifted to Lucas atoms.\r\nIn particular, one can prove analogues of theorems of Gauss and Lucas, deduce reduction formulas, and evaluate the $P_d(s,t)$ at various specific values of the variables. This is joint work with Jordan Tirrell based on an idea of Richard Stanley.
LOCATION:C304 Wells Hall
DTSTART:20190925T190000Z
DTEND:20190925T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19644
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19650@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Almost Mathematics
DESCRIPTION:Speaker\: Chuangtian Guan, MSU\r\n
LOCATION:C329 Wells Hall
DTSTART:20190926T140000Z
DTEND:20190926T160000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19650
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19608@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:The higher dimensional algebra of matrix product operators and quantum spin chains
DESCRIPTION:Speaker\: Corey Jones, The Ohio State University\r\nIn the context of 1D quantum spin chains, matrix product operators provide a way to study non-local operators such as translation in terms of quasi-local information. They have been used to describe a generalized form of symmetry for 1D systems on the boundary of 2D topological phases. In this talk, we will introduce some concepts of higher dimensional algebra, and a broad hypotheses about higher categories and spatially extended quantum systems. We will then explain how the collection of matrix product operators assembles into a higher (symmetric monoidal 2-) category, and discuss some implications of this. Based on joint work with David Penneys.
LOCATION:C304 Wells Hall
DTSTART:20190926T153000Z
DTEND:20190926T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19608
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19649@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Unexpected combinatorial properties of all planar measures
DESCRIPTION:Speaker\: A. Volberg/P. Mozolyako\r\nWe will start with paraproducts--operators used in PDE to prove Leibniz rule with fractional derivatives. Then we move to bi-parameter paraproducts and prove the property from the title.
LOCATION:C517 Wells Hall
DTSTART:20190926T170000Z
DTEND:20190926T175000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19649
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18580@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Holonomy perturbations of the Chern-Simons functional for lens spaces
DESCRIPTION:Speaker\: David Boozer, UCLA\r\nWe describe a scheme for constructing generating sets for Kronheimer and Mrowka's singular instanton knot homology for the case of knots in lens spaces. The scheme involves Heegaard-splitting a lens space containing a knot into two solid tori. One solid torus contains a portion of the knot consisting of an unknotted arc, as well as holonomy perturbations of the Chern-Simons functional used to define the homology theory. The other solid torus contains the remainder of the knot. The Heegaard splitting yields a pair of Lagrangians in the traceless $SU(2)$-character variety of the twice-punctured torus, and the intersection points of these Lagrangians comprise the generating set that we seek. We illustrate the scheme by constructing generating sets for several example knots. Our scheme is a direct generalization of a scheme introduced by Hedden, Herald, and Kirk for describing generating sets for knots in $S^3$ in terms of Lagrangian intersections in the traceless $SU(2)$-character variety for the 2-sphere with four punctures.
LOCATION:C304 Wells Hall
DTSTART:20190926T180000Z
DTEND:20190926T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18580
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19662@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Some kind of introduction to special relativity
DESCRIPTION:Speaker\: Keshav Sutrave, MSU\r\n(Soft) The beginning of Einstein's theory of special relativity, which gives us a way of doing physics in different reference frames (observers in motion). Specifically: "What happens when you turn on a flashlight while already moving at half the speed of light?" I will introduce time dilation and length contraction, event simultaneity, and touch on the problem in electromagnetism, using many examples.
LOCATION:C304 Wells Hall
DTSTART:20190930T190000Z
DTEND:20190930T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19662
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19612@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Root systems - a powerful tool for classification
DESCRIPTION:Speaker\: Joshua Ruiter, Michigan State\r\nRoot systems arose historically as a tool for classifying semisimple Lie algebras, but they can also be understood without that context. I will describe several concrete examples of root systems, with plenty of pictures. I will describe how to associate a special graph called a Dynkin diagram to a root system, and briefly describe the classification of root systems. If time allows, I will describe some of the applications to classifying semisimple Lie algebras and reductive algebraic groups. All you need to know to understand my talk is how to compute dot products on $\mathbb{R}^n$.
LOCATION:C304 Wells Hall
DTSTART:20190930T203000Z
DTEND:20190930T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19612
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19663@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Chern-Simons functional as a Morse function
DESCRIPTION:Speaker\: Keshav Sutrave, MSU\r\n
LOCATION:C117 Wells Hall
DTSTART:20191001T160000Z
DTEND:20191001T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19663
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19667@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Double Bott-Samelson cell and the moduli space of microlocal rank-1 sheaves
DESCRIPTION:Speaker\: Daping Weng, MSU\r\nShende, Treumann, and Zaslow gave a combinatorial description of the moduli space of microlocal rank-1 sheaves in their paper “Legendrian Knots and Constructible sheaves”. Following a result of Guillermou, Kashiwara, and Schapira, this moduli space is an invariant of Legendrian links. In this talk, I will review the definition and the cluster structure on the (undecorated) double Bott-Samelson cells, and show that in the cases of positive braids of Dynkin type A_r, the undecorated double Bott-Samelson cells are isomorphic to moduli spaces of microlocal rank-1 sheaves associated to the corresponding braid closures. As a corollary, the undecorated double Bott-Samelson cells of Dynkin type A_r are also Legendrian link invariants for positive braid closures. If time allows, I will also talk about how to count F_q points on the undecorated double Bott-Samelson cells.
LOCATION:C204A Wells Hall
DTSTART:20191001T190000Z
DTEND:20191001T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19667
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19646@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Toward Re-humanizing Mathematics Education: Participatory Approaches to Noticing in Mathematics Classrooms
DESCRIPTION:Speaker\: Victoria Hand , University of Colorado, Boulder, Elizabeth Mendoza, University of California, Irvine, Justin TenEyck, “I have a Dream” Foundation of Boulder County\r\nResearchers are increasingly calling for participatory approaches to educational research that center the voices, experiences, and participation of minoritized communities. This talk will report on the Co-Attend research project, which is grounded in a participatory approach to mathematics teacher noticing. The project involves mathematics teachers, leaders of local community-based organizations and university researchers in collectively understanding expansive, multisensory noticing that supports re-humanizing practices in mathematics classrooms. All participants are positioned as researchers and co-analyze project data in video club meetings and summer institutes. We will describe emerging findings from the project, both in terms of the noticing framework, as well as the participatory process.
LOCATION:252 EH
DTSTART:20191002T190000Z
DTEND:20191002T203000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19646
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19664@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Non-archimedean Banach algebras vis commutative algebra
DESCRIPTION:Speaker\: Zhihao Zhao, MSU\r\n
LOCATION:C329 Wells Hall
DTSTART:20191003T140000Z
DTEND:20191003T160000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19664
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18586@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:On Geodesic Triangles in the Hyperbolic Plane
DESCRIPTION:Speaker\: Rita Gitik, Michigan\r\nLet M be an orientable hyperbolic surface without boundary and\r\nlet c be a closed geodesic in M. We prove that any side of any triangle formed by distinct lifts of c in the hyperbolic plane is shorter than c. The talk will be presented for advanced undergraduate and beginning graduate students.\r\n
LOCATION:C304 Wells Hall
DTSTART:20191003T180000Z
DTEND:20191003T185000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18586
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19653@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Complexity, 3-Manifolds, and Zombies
DESCRIPTION:Speaker\: Joe Melby, MSU\r\nAn important invariant of a path-connected topological space X is the number of homomorphisms from the fundamental group of X to a finite, non-abelian, simple group G. Kuperberg and Samperton proved that, although these invariants can be powerful, they are often computationally intractable, particularly when X is an integral homology 3-sphere. More specifically, they prove that the problem of counting such homomorphisms is #P-complete via a reduction from a known #P-complete circuit satisfiability problem. Their model constructs X from a well-chosen Heegaard surface and a mapping class in its Torelli group. We will introduce the basics of complexity for counting problems, summarize the reduction used by K-S to bound the problem of counting homomorphisms, and discuss some of the topological and quantum computing implications of their results.
LOCATION:C304 Wells Hall
DTSTART:20191007T190000Z
DTEND:20191007T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19653
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19671@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Recent results of GCD problems on almost $S$-units and recurrences
DESCRIPTION:Speaker\: Zheng Xiao, MSU\r\nThe GCD problem is one of the major problems in Diophantine Geometry. Corvaja, Zannier and Bugeaud first gave a fundamental result on GCD of integers powers and then generalized to rational numbers and algebraic numbers by many mathematicians. In this talk I will introduce recent GCD results on $S$-units due to Levin and generalize to almost $S$-units. I will give the definition of almost units and present the main theorem of GCD on multivariable polynomials, which is lead to a result about recurrence sequences. If time allows, I will also introduce Silverman’s generalized GCD along the blow up of a closed subscheme and apply to abelian surface case and its connection to Vojta’s conjecture.
LOCATION:C517 Wells Hall
DTSTART:20191007T203000Z
DTEND:20191007T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19671
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19674@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:A sketch of the construction of instanton Floer homology
DESCRIPTION:Speaker\: Thomas Walpuski, MSU\r\n
LOCATION:C117 Wells Hall
DTSTART:20191008T160000Z
DTEND:20191008T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19674
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19679@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Double Bott-Samelson cell and the moduli space of microlocal rank-1 sheaves
DESCRIPTION:Speaker\: Daping Weng, MSU\r\nShende, Treumann, and Zaslow gave a combinatorial description of the moduli space of microlocal rank-1 sheaves in their paper “Legendrian Knots and Constructible sheaves”. Following a result of Guillermou, Kashiwara, and Schapira, this moduli space is an invariant of Legendrian links. In this talk, I will review the definition and the cluster structure on the (undecorated) double Bott-Samelson cells, and show that in the cases of positive braids of Dynkin type A_r, the undecorated double Bott-Samelson cells are isomorphic to moduli spaces of microlocal rank-1 sheaves associated to the corresponding braid closures. As a corollary, the undecorated double Bott-Samelson cells of Dynkin type A_r are also Legendrian link invariants for positive braid closures. If time allows, I will also talk about how to count F_q points on the undecorated double Bott-Samelson cells.
LOCATION:C204A Wells Hall
DTSTART:20191008T190000Z
DTEND:20191008T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19679
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19675@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Cocycles valued in motivic cohomology
DESCRIPTION:Speaker\: Romyar Sharifi, UCLA\r\nI will describe joint work in progress with Akshay Venkatesh on the construction of 1-cocycles on $\mathrm{GL}_2(\mathbb{Z})$ valued in a limit of second motivic cohomology groups of open subschemes of the square of (1) the multiplicative group over the rationals and (2) a universal elliptic curve. I’ll explain how these cocycles specialize to homomorphisms taking modular symbols to special elements in second cohomology groups of cyclotomic fields and modular curves in the respective cases.
LOCATION:C304 Wells Hall
DTSTART:20191009T190000Z
DTEND:20191009T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19675
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19681@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:An ergodic theorem for homogeneously distributed quantum channels with applications to matrix product states
DESCRIPTION:Speaker\: Jeffrey Schenker, Michigan State University\r\nQuantum channels represent the most general physical evolution of a quantum system through unitary evolution and a measurement process. Mathematically, a quantum channel is a completely positive and trace preserving linear map on the space of $D\times D$ matrices. We consider ergodic sequences of channels, obtained by sampling channel valued maps along the trajectories of an ergodic dynamical system. The repeated composition of these maps along such a sequence could represent the result of repeated application of a given quantum channel subject to arbitrary correlated noise. It is physically natural to assume that such repeated compositions are eventually strictly positive, since this is true whenever any amount of decoherence is present in the quantum evolution. Under such an hypothesis, we obtain a general ergodic theorem showing that the composition of maps converges exponentially fast to a rank-one -- “entanglement breaking’’ – channel. We apply this result to describe the thermodynamic limit of ergodic matrix product states and prove that correlations of observables in such states decay exponentially in the bulk. (Joint work with Ramis Movassagh)
LOCATION:C304 Wells Hall
DTSTART:20191010T153000Z
DTEND:20191010T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19681
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19670@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Embedding on bi-tree
DESCRIPTION:Speaker\: Pavel Mozolyako, MSU\r\n
LOCATION:C517 Wells Hall
DTSTART:20191010T170000Z
DTEND:20191010T175000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19670
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18597@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Modular symbols and the arithmetic of cyclotomic fields
DESCRIPTION:Speaker\: Romyar Sharifi, UCLA\r\nThe arithmetic of cyclotomic fields, and the structure of their class groups, has been studied since the time of Kummer in connection with Fermat’s Last Theorem. The work of Ribet in 1976 uncovered a subtle influence of the geometry of modular curves on this structure. I’ll discuss how this connection goes even deeper and define a surprisingly explicit map from the homology group of a modular curve to a K-group related to the class group of a cyclotomic field. I’ll then indicate how this is turning out to be just one instance of a more general phenomenon, touching briefly on joint work with Takako Fukaya and Kazuya Kato and separate joint work with Akshay Venkatesh.
LOCATION:C304 Wells Hall
DTSTART:20191010T201000Z
DTEND:20191010T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18597
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19633@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Randomized algorithms for low-rank tensor decompositions
DESCRIPTION:Speaker\: Arvind Krishna Saibaba, North Carolina State University \r\nMany applications in data science and scientific computing require the working with large-scale datasets that are expensive to store and manipulate. These datasets have inherent multidimensional structure that can be exploited in order to efficiently compress and\r\nstore them in an appropriate tensor format. In recent years, randomized matrix methods have been used to efficiently and accurately compute low-rank matrix decompositions. Motivated by this success, we develop several randomized algorithms for compressing\r\ntensor datasets in the Tucker format. We present probabilistic error analysis for our algorithms and numerical results on several datasets: synthetic test tensors, and realistic applications including the compression of facial image samples in the Olivetti database, and word counts in the Enron email dataset.\r\n\r\nJoint work with Rachel Minster (NC State) and Misha Kilmer (Tufts)
LOCATION:C304 Wells Hall
DTSTART:20191011T201000Z
DTEND:20191011T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19633
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19654@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:An introduction to intersection forms: Taking K3 surface as an example
DESCRIPTION:Speaker\: Zhe Zhang, MSU\r\nI’ll define intersection product both on 4 manifolds and in the algebraic geometry setting, then introduce the blow up technique and give some easy examples. After that I will jump to K3 surface, give definition and constructions, and talk a little bit about the elliptic fibrations of K3. If I still have time, I will talk about the relation between intersection form and characteristic classes.
LOCATION:C304 Wells Hall
DTSTART:20191014T190000Z
DTEND:20191014T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19654
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19614@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:The Isomorphism Theorems in an Abelian Category
DESCRIPTION:Speaker\: Dan Normand, Harvard University\r\nIt is often said that abelian categories are where homology can "naturally" occur. As the notion of an isomorphism is indispensable to the study of homology---and an innate aspect of a category---, one would hope that there are analogues to the usual three isomorphism theorems of algebra in an arbitrary abelian category. In this [talk] we show that there are indeed such analogues, and we spend time developing the machinery to implement them
LOCATION:C304 Wells Hall
DTSTART:20191014T203000Z
DTEND:20191014T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19614
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19680@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Linear analysis on cylindrical-end manifolds
DESCRIPTION:Speaker\: Wenchuan Tian, MSU\r\nDonaldson Ch. 3
LOCATION:C117 Wells Hall
DTSTART:20191015T160000Z
DTEND:20191015T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19680
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20682@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Fenchel--Nielsen coordinates on Riemann surfaces and cluster algebras
DESCRIPTION:Speaker\: Leonid Chekhov, MSU\r\nIt is a 30(at least)-year old subject: it is known since long that both the standard Fenchel--NIelsen (lengths--twists) coordinates and (Y-)cluster coordinates (if we have holes) result in the same Goldman bracket on the set of geodesic functions on Riemann surfaces. The proof (of "local" nature in the first case and of "global" in the second) implies that these two sets of coordinates realise the same Poisson algebra. Nevertheless, constructing a direct transition between these two sets was elusive mainly due to complexity of the transition. For a sphere with 4 holes and torus with one hole, the corresponding formulas were obtained by Nekrasov, Rosly and Shatashvili in 2011. I present some preliminary results on the corresponding algebras in the general case and discuss possible relations to objects called Yang--Yang functionals.
LOCATION:C304 Wells Hall
DTSTART:20191015T170500Z
DTEND:20191015T180500Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20682
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19677@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:New and Old Combinatorial Identities Part I
DESCRIPTION:Speaker\: Aklilu Zeleke, MSU\r\nBinomial coefficients $n \choose k$ appear in different areas of mathematics (in Pascal's triangle, counting problems and computing probabilities to name few). There are also many identities that involve binomial coefficients. In this talk we will discuss new and old identities that represent positive integers and in some cases real numbers. These identities are derived from studying the asymptotic behavior of the roots of a generalized Fibonacci polynomial sequence\r\ngiven by $F_{j}(x)=x^{j}-...-x-1$.
LOCATION:C304 Wells Hall
DTSTART:20191016T190000Z
DTEND:20191016T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19677
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19632@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Bubble Tree Convergence of Parametrized Associative Submanifolds
DESCRIPTION:Speaker\: Jesse Madnick , McMaster University \r\nIn symplectic geometry, part of Gromov's Compactness Theorem asserts that sequences of holomorphic curves with bounded energy have subsequences that converge to bubble trees, and that both energy and homotopy are preserved in this "bubble tree limit." In $G_2$ geometry, the analogues of holomorphic maps are the "associative Smith maps." In this talk, we'll see that familiar analytic features of holomorphic maps also hold for associative Smith maps. In particular, we'll describe how sequences of associative Smith maps give rise to bubble trees, and how energy and homotopy are again preserved in the limit. This is joint work with Da Rong Cheng and Spiro Karigiannis.
LOCATION:C304 Wells Hall
DTSTART:20191017T180000Z
DTEND:20191017T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19632
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18588@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Higher convexity for complements of tropical objects
DESCRIPTION:Speaker\: Frank Sottile, Texas A&M University\r\nGromov generalized the notion of convexity for open subsets \r\nof $\mathbf{R}^n$ with hypersurface boundary, defining $k$-convexity, or\r\nhigher convexity and Henriques applied the same notion to \r\ncomplements of amoebas. He conjectured that the complement \r\nof an amoeba of a variety of codimension $k+1$ is $k$-convex. \r\nI will discuss work with Mounir Nisse in which we study the \r\nhigher convexity of complements of coamoebas and of tropical \r\nvarieties, proving Henriques' conjecture for coamoebas and \r\nestablishing a form of Henriques' conjecture for tropical varieties in some cases.
LOCATION:C304 Wells Hall
DTSTART:20191017T201000Z
DTEND:20191017T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18588
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19626@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:The talk this week has been cancelled.
DESCRIPTION:Speaker\: \r\nThe talk this week has been cancelled.
LOCATION:C304 Wells Hall
DTSTART:20191018T201000Z
DTEND:20191018T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19626
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19683@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:When the Game Changes: The Development of Student Agency and Autonomy in Challenging Undergraduate Mathematics
DESCRIPTION:Speaker\: Jack Smith, MSU, Shiv Karunakaran, MSU\r\nIn their pre-college and introductory collegiate mathematics coursework, students learn that mathematics centrally, if not exclusively involves computation. But many who pursue STEM disciplines routinely could encounter a quite different kind of mathematical work: The composition and evaluation of formal mathematical arguments, including proofs. The locus of this shift in mathematical activity on the MSU campus is MTH 299, Transitions, which introduces students to the basics of proof and argument. In the talk, we will present our current work conceptualizing agency and autonomy, the students who take the course, the challenges they face, and what we are learning about their experience in the course. We hope that these lessons will prove useful to all efforts to enrich introduction to proof mathematics courses.
LOCATION:115 Erickson Hall
DTSTART:20191021T160000Z
DTEND:20191021T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19683
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19655@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:The Ends of Hyperbolic Manifolds
DESCRIPTION:Speaker\: Brandon Bavier, MSU\r\nWhen studying knots, we can often get a lot of information by removing the knot from space, and looking at the knot complement. It's pretty natural to ask, then, what happens to the area close to the removed knot? We call these areas cusps, and, in the case of hyperbolic knots, the cusp alone can tell us quite a lot. In this talk, we will give an introduction to these cusps, including their uses in topology, as well as how to find invariants from them.
LOCATION:C304 Wells Hall
DTSTART:20191021T190000Z
DTEND:20191021T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19655
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20683@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Instructional Faculty Observations and Evaluation
DESCRIPTION:Speaker\: Andy Krause, MSU\r\nWe'll revisit the Instructional Faculty observation structure (from our meeting in Spring) and organize classroom observations for the fall.
LOCATION:C109 Wells Hall
DTSTART:20191021T201000Z
DTEND:20191021T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20683
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19629@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Serre Duality I
DESCRIPTION:Speaker\: Yu Shen, Michigan State\r\nSerre duality was first proved by Serre in 1950s. It is a very useful tool in algebraic and complex geometry. In this lecture, I will use Čech cohomology to prove Serre duality of projective varieties. If time permits, I would like to talk about some applications of it.
LOCATION:C304 Wells Hall
DTSTART:20191021T203000Z
DTEND:20191021T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19629
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20684@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Linear analysis on cylindrical-end manifolds (continued)
DESCRIPTION:Speaker\: Gorapada Bera, MSU\r\n
LOCATION:C117 Wells Hall
DTSTART:20191022T160000Z
DTEND:20191022T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20684
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20686@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Fenchel--Nielsen coordinates on Riemann surfaces and cluster algebras
DESCRIPTION:Speaker\: Leonid Chekhov, MSU\r\nIt is a 30(at least)-year old subject: it is known since long that both the standard Fenchel--NIelsen (lengths--twists) coordinates and (Y-)cluster coordinates (if we have holes) result in the same Goldman bracket on the set of geodesic functions on Riemann surfaces. The proof (of "local" nature in the first case and of "global" in the second) implies that these two sets of coordinates realise the same Poisson algebra. Nevertheless, constructing a direct transition between these two sets was elusive mainly due to complexity of the transition. For a sphere with 4 holes and torus with one hole, the corresponding formulas were obtained by Nekrasov, Rosly and Shatashvili in 2011. I present some preliminary results on the corresponding algebras in the general case and discuss possible relations to objects called Yang--Yang functionals.
LOCATION:C204A Wells Hall
DTSTART:20191022T190000Z
DTEND:20191022T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20686
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19676@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Local-global principle for norms over semi-global fields
DESCRIPTION:Speaker\: Sumit Chandra Mishra, Emory University\r\nLet $K$ be a complete discretely valued field with\r\nresidue field $\kappa$.\r\n\r\nLet $F$ be a function field in one variable over $K$\r\n\r\nand $\mathscr{X}$ a regular proper model of $F$\r\n\r\nwith reduced special fibre $X$ a union of regular curves\r\n\r\nwith normal crossings.\r\n\r\nSuppose that the graph associated to\r\n\r\n$\mathscr{X}$ is a tree (e.g. $F = K(t)$).\r\n\r\nLet $L/F$ be a Galois extension of degree $n$ with Galois group $G$\r\n\r\nand $n$ coprime to char$(\kappa)$.\r\n\r\nSuppose that $\kappa$ is algebraically closed field or\r\n\r\na finite field containing a primitive $n^{\rm th}$ root of unity.\r\n\r\nThen we show that an element in $F^*$ is a norm\r\n\r\nfrom the extension $L/F$ if it is a norm from the\r\n\r\nextensions $L\otimes_F F_\nu/F_\nu$\r\n\r\nfor all discrete valuations $\nu$ of $F$.
LOCATION:C304 Wells Hall
DTSTART:20191023T190000Z
DTEND:20191023T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19676
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19638@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Entanglement bounds in the XXZ spin chain
DESCRIPTION:Speaker\: Houssam Abdul-Rahman, U Arizona\r\nWe consider the XXZ chain in the Ising phase. The particle number conservation property is used to write the Hamiltonian in a hard-core particles formulation over the $N$-symmetric product of graphs, where $N\in\mathbb{N}_0$ is the number of conserved particle. The droplet regime corresponds to a band at the bottom of the spectrum of the model consisting of a connected set (a droplet) of down-spins, up to an exponential error. It is interesting to know that in the formulation over the $N$-symmetric product graphs, with a fixed $N\geq 1$, the XXZ chain can be seen as a one-dimensional model only when it is restricted to droplet states. This justifies the recent many-body localization indicators proved in the droplet regime by Elgart/Klein/Stolz and Beaud/Warzel for the disordered model, including an area law of arbitrary states in that localized phase. As a first step beyond the droplet regime, we show that the entanglement of arbitrary states above the droplet regime (associated with multiple droplets/clusters) does not follow area laws, and instead, it follows a logarithmically corrected (enhanced) area law. We will comment on the effects of disorder on entanglement, and show how our results hint a phase transition.\r\n(joint work with C. Fischbacher and G. Stolz, arXiv1907.11420) \r\n\r\n
LOCATION:C304 Wells Hall
DTSTART:20191024T153000Z
DTEND:20191024T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19638
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19641@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Obstructing Lagrangian link cobordisms via Heegaard Floer homology.
DESCRIPTION:Speaker\: Lev Tovstopyat-Nelip, MSU\r\nI'll explain how an invariant of Legendrian links in knot Floer homology can be used to obstruct the existence of decomposable Lagrangian link cobordisms in a very general setting. The argument involves braiding the ends of the cobordism about open books and appealing to an algebraic property of the Legendrian invariant called comultiplication. Much of the talk will be spent describing the topological and contact geometric ingredients.
LOCATION:C304 Wells Hall
DTSTART:20191024T180000Z
DTEND:20191024T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19641
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18600@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Geodesic X-ray Transforms and Boundary Rigidity
DESCRIPTION:Speaker\: Robin Graham, University of Washington\r\nThis talk will introduce the problem of injectivity and\r\ninversion of geodesic X-ray transforms in various geometric settings. The\r\nassociated nonlinear boundary rigidity problem, which consists of\r\ndetermining a Riemannian metric on a compact manifold-with-boundary from\r\nthe lengths of its geodesics joining boundary points, will also be\r\ndiscussed. Classical results and recent progess will be described,\r\nincluding current research on the analogous questions in the setting of \r\nasymptotically hyperbolic manifolds.
LOCATION:C304 Wells Hall
DTSTART:20191024T201000Z
DTEND:20191024T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18600
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19656@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Introduction to the Yang-Mills equation
DESCRIPTION:Speaker\: Arman Tavakoli, MSU\r\nThe Yang-Mills equation is a celebrated topic that is studied in differential geometry and particle physics. We will motivate the equation as a generalization of Maxwell's equations, define the relevant geometrical objects and discuss their properties.
LOCATION:C304 Wells Hall
DTSTART:20191028T190000Z
DTEND:20191028T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19656
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19673@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Partial differential equations from evolutionary ecology
DESCRIPTION:Speaker\: Olga Turanova, MSU\r\nIn collaboration with the AWM Student Chapter, we are most happy to welcome Professor Turanova to MSU! The abstract of her talk is:\r\n\r\nI will describe the analysis of some PDEs that arise as models of ecological and evolutionary processes. There will be (some discussion of) poisonous toads!
LOCATION:C304 Wells Hall
DTSTART:20191028T200000Z
DTEND:20191028T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19673
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19630@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Serre Duality II
DESCRIPTION:Speaker\: Yu Shen, Michigan State\r\nSerre duality was first proved by Serre in 1950s. It is a very useful tool in algebraic and complex geometry. In this lecture, I will use Čech cohomology to prove Serre duality of projective varieties. If time permits, I would like to talk about some applications of it.
LOCATION:C517 Wells Hall
DTSTART:20191028T203000Z
DTEND:20191028T213000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19630
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20685@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Gauge theory and tubular ends
DESCRIPTION:Speaker\: Gorapada Bera, MSU\r\n
LOCATION:C117 Wells Hall
DTSTART:20191029T160000Z
DTEND:20191029T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20685
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20692@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Character varieties, Coulomb branches, and clusters.
DESCRIPTION:Speaker\: Alexander Shapiro, UC Berkeley\r\nQuantum groups admit two different geometric realizations: as quantized character varieties and as quantized Coulomb branches of certain gauge theories. These realizations endow a quantum group with two, a priori different, cluster structures. In this talk I will show these structures, explain why they coincide, and say what they have to do with Gelfand-Tsetlin subalgebras, higher rank Fenchel–Nielsen coordinates, and modular functor from higher Teichmüller theory. This talk will be based on joint works with Gus Schrader.
LOCATION:C204A Wells Hall
DTSTART:20191029T190000Z
DTEND:20191029T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20692
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19678@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:New and Old Combinatorial Identities Part II
DESCRIPTION:Speaker\: Aklilu Zeleke, MSU\r\nUsing a probabilistic approach, we derive some interesting identities involving beta functions. These results generalize certain well-known combinatorial identities involving binomial coefficients and gamma functions.
LOCATION:C304 Wells Hall
DTSTART:20191030T190000Z
DTEND:20191030T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19678
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19619@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Classification of links with Khovanov homology of minimal rank
DESCRIPTION:Speaker\: Boyu Zhang, Princeton University\r\nIn this talk, I will present a classification of links whose Khovanov homology has minimal rank, which answers a question asked by Batson and Seed. The proof is based on an excision formula for singular instanton Floer homology that allows the excision surface to intersect the singularity. We will use the excision theorem to define an instanton Floer homology for tangles on sutured manifolds, and show that its gradings detect the generalized Thurston norm for punctured surfaces. This is joint work with Yi Xie.
LOCATION:C304 Wells Hall
DTSTART:20191031T180000Z
DTEND:20191031T190000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19619
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-18589@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Dynamics in models of coagulation and fragmentation
DESCRIPTION:Speaker\: Robert Pego, Carnegie Mellon University\r\nCoaglation-fragmentation equations are simple, nonlocal models for evolution of the size distribution of clusters, appearing widely in science and technology. But few general analytical results characterize their dynamics. Solutions can exhibit self-similar growth, singular mass transport, and weak or slow approach to equilibrium. I will review some recent results in this vein, discussing: the cutoff phenomenon (as in card shuffling) for Becker-Doering equilibration; stationary and spreading profiles in a data-driven model of fish school size; and temporal oscillations recently found in models lacking detailed balance. A special role is played by Bernstein transforms and complex function theory for Pick or Herglotz functions.
LOCATION:C304 Wells Hall
DTSTART:20191031T201000Z
DTEND:20191031T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=18589
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20694@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:A unified approach to three themes in harmonic analysis
DESCRIPTION:Speaker\: Victor Lie, Purdue University\r\n
LOCATION:C304 Wells Hall
DTSTART:20191101T170000Z
DTEND:20191101T180000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20694
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19657@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Introduction to Riemannian Holonomy
DESCRIPTION:Speaker\: Gorapada Bera, MSU\r\nThe holonomy group of a Riemannian manifold exhibits various geometric structures compatible with the metric. In 1955, M.Berger classified all possible Riemannian holonomy groups. Studying all these are more than one semester subject. So, in this talk after a brief introduction we overview very basics of these holonomy groups.
LOCATION:C304 Wells Hall
DTSTART:20191104T200000Z
DTEND:20191104T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19657
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19672@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Arithmetic intersection theory and Arakelov's Hodge Index Theorem
DESCRIPTION:Speaker\: Zheng Xiao, Michigan State\r\nThe famous Mordell-Weil conjecture was first proved by Faltings in a classical way, then Vojta gave an alternative proof using arithmetic Arakelov geometry, which is one big motivation for developing Arakelov theory into a mature tool. In this talk I will introduce Neron functions and divisors, which is an arithmetic approach to define divisors rather than classical algebraic geometry. We shall also cover arithmetic chow groups and the arithmetic intersection number. In the end I will present Neron symbols and use it to give a sketch proof of Arakelov’s Hodge Index Theorem.
LOCATION:C304 Wells Hall
DTSTART:20191104T213000Z
DTEND:20191104T223000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19672
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20696@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Instanton homology of Seifert-fibered homology 3-spheres
DESCRIPTION:Speaker\: Alex Waldron, MSU\r\nFintushel & Stern, 1990
LOCATION:C117 Wells Hall
DTSTART:20191105T170000Z
DTEND:20191105T183000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20696
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20689@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Bi-ordinary modular forms
DESCRIPTION:Speaker\: Carl Wang-Erickson, University of Pittsburg\r\nIt is known that p-ordinary cuspidal Hecke eigenforms give rise to 2-dimensional global Galois representations which become reducible after restriction to a decomposition group at p. For which such forms is this restriction not only reducible but also splittable? Complex multiplication (CM) forms satisfy this p-local property, but is such a restrictive global property as CM necessary? In classical weights at least 2, it is expected that this is the case. We present a construction of "bi-ordinary" p-adic modular forms, which can measure exceptions to this expectation. We also give evidence that there are non-CM but p-locally splittable forms in p-adic weights. This is joint work with Francesc Castella.
LOCATION:C304 Wells Hall
DTSTART:20191105T200000Z
DTEND:20191105T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20689
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19648@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Normal rulings and augmentation varieties
DESCRIPTION:Speaker\: Dan Rutherford, Ball State University\r\nNormal rulings are combinatorial structures associated to the front diagrams of 1-dimensional Legendrian knots in R^3. They were introduced independently by Fuchs and Chekanov-Pushkar in the context of augmentations of the Legendrian DG-algebra and generating families. In this talk I will present joint work with B. Henry in which we construct a decomposition of the augmentation variety into disjoint pieces indexed by normal rulings. The pieces of the decomposition are products of algebraic tori and affine spaces with dimensions determined by the combinatorics of the ruling. As a consequence, the ruling polynomial invariants of Chekanov-Pushkar are seen to be equivalent to augmentation number invariants defined by counting augmentations to finite fields. The construction of the decomposition is based on considering Morse complex sequences which are combinatorial analogs of generating families.
LOCATION:C204A Wells Hall
DTSTART:20191105T200000Z
DTEND:20191105T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19648
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20695@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Variations of cops and robbers on infinite graphs
DESCRIPTION:Speaker\: Robert Bell, MSU\r\nThe game of cops and robbers is a two player pursuit and evasion game played on a discrete graph G. We study a variation of the classical rules which leads to a different invariant when G is an infinite graph. In this variation, called "weak cops and robbers," the cops win by preventing the robber from visiting any vertex infinitely often. In the classical game, if G is connected and planar, then the cops can always win if there are at least three cops. We prove that this is true in the weak game if G is a locally finite plane graph with no vertex accumulation points.
LOCATION:C304 Wells Hall
DTSTART:20191106T200000Z
DTEND:20191106T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20695
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19645@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Derivation of a ternary Boltzmann system
DESCRIPTION:Speaker\: Ioakeim Ampatzoglou, University of Texas, Austin\r\nIn this talk work we present a rigorous derivation of a new kinetic equation describing the limiting behavior of a classical system of particles with three particle instantaneous interactions, which are modeled using\r\na non-symmetric version of a ternary distance. The equation, which we call ternary Boltzmann equation, can be understood as a step towards modeling a dense gas in non-equilibrium. This is a joint work with Natasa Pavlović.
LOCATION:C304 Wells Hall
DTSTART:20191106T211000Z
DTEND:20191106T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19645
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20698@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Schubert Varieties in Partial Flag Manifolds and Generalized Severi-Brauer Varieties
DESCRIPTION:Speaker\: Marios Velivasakis, University of Western Ontario\r\nSchubert varieties form one of the most important classes of singular algebraic varieties. They are also a kind of moduli spaces. One problem is that these varieties are not easy to understand and manipulate using only their geometric nature. In this talk, we will discuss about Schubert varieties and present a way to characterize them combinatorially. In addition, we will discuss how they relate to Severi-Brauer varieties SB(d,A) and how we can use their combinatorial description to answer questions about subvarieties of SB(d,A)
LOCATION:C329 Wells Hall
DTSTART:20191107T160000Z
DTEND:20191107T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20698
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19639@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Localization for the Anderson--Bernoulli model on the integer lattice
DESCRIPTION:Speaker\: Charles Smart, U Chicago\r\nAbstract: I will give a brief mathematical introduction to Anderson localization followed by a discussion of my recent work with Jian Ding. In our work we establish localization near the edge for the Anderson Bernoulli model on the two dimensional lattice. Our proof follows the program of Bourgain--Kenig and uses a new unique continuation result inspired by Buhovsky--Logunov--Malinnikova--Sodin. I will also discuss recent work of by Li and Zhang on the three dimensional case.
LOCATION:C304 Wells Hall
DTSTART:20191107T163000Z
DTEND:20191107T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19639
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19643@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Sketching and Clustering Metric Measure Spaces
DESCRIPTION:Speaker\: Kritika Singhal, Ohio State University\r\nTwo important optimization problems in the analysis of geometric data sets are clustering and simplification (sketching) of data. Clustering refers to partitioning a dataset, according to some rule, into sets of smaller size with the aim of extracting important information from the data. Sketching, or simplification of data, refers to approximating the input data with another dataset of much smaller size in such a way that properties of the input dataset are retained by the smaller dataset. In this sense, sketching facilitates understanding of the data.\r\n\r\nThere are many clustering methods for metric spaces (mm spaces) already present in literature, such as k-center clustering, k-median clustering, k-means clustering, etc. A natural method for obtaining a k-sketch of a metric space (mm space) is by viewing the space of all metric spaces (mm space) as a metric under Gromov-Hausdorff (Gromov-Wasserstein) distance, and then determining, under this distance, the k point metric space (mm space) closest to the input metric space (mm space).\r\n\r\nThese two problems of sketching and clustering, a priori, look completely unrelated. However, we establish a duality i.e. an equivalence between these notions of sketching and clustering. For metric spaces, we consider the case where the clustering objective is minimizing the maximum cluster diameter. We show that the ratio between the sketching and clustering objectives is constant over compact metric spaces.\r\n\r\nWe extend these results to the setting of metric measure spaces where we prove that the ratio of sketching to clustering objectives is bounded both above and below by some universal constants. In this setting, the clustering objective involves minimizing various notions of the $\ell_p$-diameters of the clusters.\r\n\r\nWe also identify procedures/maps that transform a solution of the sketching problem to a solution of the clustering problem, and vice-versa. These maps give rise to algorithms for performing these transformations and, by virtue of these algorithms, we are able to obtain an approximation to the k-sketch of a metric measure space (metric space) using known approximation algorithms for the respective clustering objectives. This is joint work with Facundo Memoli and Anastasios Sidiropoulos, and is available online at https://arxiv.org/abs/1801.00551.\r\n\r\n
LOCATION:C304 Wells Hall
DTSTART:20191108T211000Z
DTEND:20191108T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19643
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20702@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Embedding the CMP Curriculum into a Digital Collaborative Platform
DESCRIPTION:Speaker\: Betty Phillips, MSU, AJ Edson, MSU\r\nThe context for the work is transitioning the Connected Mathematics, an established\r\nproblem-based curriculum, to a digital environment. In CMP, mathematical understandings are embedded in tasks which are carefully sequenced to build deep understanding of important mathematical ideas. In this session, we report on curriculum research and development efforts to leverage digital technologies to support student collaboration and enhance students’ productive disciplinary engagement in mathematics. Bring a laptop to partake in the collaborative environment.
LOCATION:115 Erickson Hall
DTSTART:20191111T170000Z
DTEND:20191111T180000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20702
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19658@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Properties of Busemann function on manifolds with nonnegative sectional curvature outside of a compact set
DESCRIPTION:Speaker\: Wenchuan Tian, MSU\r\nBusemann functions are useful. Cheeger and Gromoll used them to prove the splitting theorem for manifolds with nonnegative ricci curvature that contains a line. Yau used them to prove that complete noncompact manifolds with nonnegative Ricci curvature have at least linear volume growth.\r\n\r\nIn a paper called "Positive Harmonic Functions on Complete Manifolds with Non-Negative Curvature Outside a Compact Set" Peter Li and Luen-Fai Tam also used Busemann function to show the existence of positive harmonic functions. I will talk about Li and Tam's proof of properties of Busemann function. The proof only uses Toponogov theorem and cosine law. The results of the proof is useful for the subsequent analysis part of the paper.
LOCATION:C304 Wells Hall
DTSTART:20191111T200000Z
DTEND:20191111T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19658
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20699@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Field norm for algebraic groups, with a view towards non-split tori
DESCRIPTION:Speaker\: Joshua Ruiter, Michigan State\r\nField norm maps are useful in many areas of algebra, such as Galois theory. Using the language of (affine) algebraic groups, I will place the field norm in a larger context, as a particular instance of a certain natural transformation. This will set us up for my talk the following week, on special subgroups of algebraic groups called tori, and what it means for such tori to be split or non-split. In particular, the generalized norm will provide a (somewhat) concrete example of a non-split torus.
LOCATION:C304 Wells Hall
DTSTART:20191111T213000Z
DTEND:20191111T223000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20699
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20704@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:On the surgery exact triangle in Heegaard Floer homology
DESCRIPTION:Speaker\: Lev Tovstopyat, MSU\r\n
LOCATION:C117 Wells Hall
DTSTART:20191112T170000Z
DTEND:20191112T183000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20704
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20706@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Cop number and edge deletion, addition, or subdivision
DESCRIPTION:Speaker\: Robert Bell, MSU\r\nWe present new and old results about the effect of edge operations on the cop number of a finite graph. \r\n This project was part of the SURIEM summer REU program in 2019 at MSU.
LOCATION:C304 Wells Hall
DTSTART:20191113T200000Z
DTEND:20191113T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20706
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20703@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Regularity results for a class of Kolmogorov-Fokker-Planck equations in non-divergence form
DESCRIPTION:Speaker\: Farhan Abedin, Michigan State University\r\nThe Kolmogorov-Fokker-Planck equation is a degenerate parabolic equation arising in models of gas dynamics from kinetic theory. The operator is of the form\r\n$$\mathcal{L}_Au := \mathrm{tr}(A(v,y,t) D^2_v u) + v \cdot \nabla_yu - \partial_tu,$$ where $$u(v,y,t): \mathbb{R}^{2d+1} \to \mathbb{R} \text{ and } 0 < \lambda \mathbb{I}_d \leq A \leq \Lambda \mathbb{I}_d.$$\r\nIt is an open problem if non-negative solutions of $\mathcal{L}_A u = 0$ in $\mathbb{R}^{2d+1}$ satisfy a scale-invariant Harnack inequality, assuming the matrix coefficient $A$ is merely bounded and measurable. I will discuss recent joint work with Giulio Tralli in which progress is made on partially solving this problem.
LOCATION:C304 Wells Hall
DTSTART:20191113T211000Z
DTEND:20191113T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20703
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20711@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Time-reversal of multiple-force-point SLE$_\kappa(\underline\rho)$ with all force points lying on the same side
DESCRIPTION:Speaker\: Dapeng Zhan, MSU\r\nWe define intermediate SLE$_\kappa(\underline \rho)$ and reversed intermediate SLE$_\kappa(\underline\rho)$ processes using Appell-Lauricella multiple hypergeometric functions, and use them to describe the time-reversal of multiple-force-point chordal SLE$_\kappa(\underline \rho)$ curves in the case that all force points are on the boundary and lie on the same side of the initial point, and $\kappa $ and $\underline \rho=(\rho_1,\dots,\rho_m)$ satisfy that either $\kappa\in(0,4]$ and $\sum_{j=1}^k \rho_j>-2$ for all $1\le k\le m$, or $\kappa\in(4,8)$ and $\sum_{j=1}^k \rho_j\ge \frac{\kappa}{2}-2$ for all $1\le k\le m$.
LOCATION:C506 Wells Hall
DTSTART:20191114T200000Z
DTEND:20191114T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20711
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20707@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:What do you mean by "show"? Is it the same as "prove"?
DESCRIPTION:Speaker\: Jihye Hwang, Michigan State University\r\nStudents face a mathematical task whenever they involve in doing mathematics. We wondered whether the word used in posing question impact students’ response and we hypothesize that task provider’s intention and students’ response can be different. This talk focus on students interpretation of the different prompts, such as “prove,” “show,” “explain,” and “convince a classmate,” for proving tasks. This talk focuses on the two prompts, “prove” and “show” as the prompts are regarded as synonymous by many people, especially mathematicians. Although there exist similarities between the prompts, the result mainly demonstrates students possibly have different meaning for “prove” and “show” depending on individual and one possible relationship between the two prompts.
LOCATION:C304 Wells Hall
DTSTART:20191114T210000Z
DTEND:20191114T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20707
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19618@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Spectral gaps without frustration
DESCRIPTION:Speaker\: Marius Lemm, Harvard\r\nIn quantum spin systems, the existence of a spectral gap above the ground state has strong implications for the low-energy physics. We survey recent results establishing spectral gaps in various frustration-free spin systems by verifying finite-size criteria. The talk is based on collaborations with Abdul-Rahman, Lucia, Mozgunov, Nachtergaele, Sandvik, Yang, Young, and Wang.
LOCATION:C304 Wells Hall
DTSTART:20191115T153000Z
DTEND:20191115T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19618
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19640@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Uniqueness and non-uniqueness of steady states of aggregation-diffusion equation
DESCRIPTION:Speaker\: Yao Yao, Georgia Tech\r\nIn this talk, I will discuss a nonlocal aggregation equation with degenerate diffusion, which describes the mean-field limit of interacting particles driven by nonlocal interactions and localized repulsion. When the interaction potential is attractive, it is previously known that all steady states must be radially decreasing up to a translation, but uniqueness (for a given mass) within this class was open, except for some special interaction potentials. For general attractive potentials, we show that the uniqueness/non-uniqueness criteria are determined by the power of the degenerate diffusion, with the critical power being m=2. Namely, for m>=2, we show the steady state for any given mass is unique for any attractive potential, by tracking the associated energy functional along a novel interpolation curve. And for 1<m<2, we construct examples of smooth attractive potentials, such that there are infinitely many radially decreasing steady states of the same mass. This is a joint work with Matias Delgadino and Xukai Yan.
LOCATION:C304 Wells Hall
DTSTART:20191115T211000Z
DTEND:20191115T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19640
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19659@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Computations in Topological CoHochschild Homology
DESCRIPTION:Speaker\: Sarah Klanderman, MSU\r\nHochschild homology (HH) is a classical algebraic invariant of rings that can be extended topologically to be an invariant of ring spectra, called topological Hochschild homology (THH). There exists a dual theory for coalgebras called coHochschild homology (coHH), and in recent work Hess and Shipley defined an invariant of coalgebra spectra called topological coHochschild homology (coTHH). In this talk we will discuss coTHH calculations and the tools needed to do them.
LOCATION:C304 Wells Hall
DTSTART:20191118T200000Z
DTEND:20191118T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19659
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20700@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Split and non-split tori
DESCRIPTION:Speaker\: Joshua Ruiter, Michigan State\r\nTori are an important structural aspect of algebraic groups, and "split" vs "non-split" tori are especially important. Unfortunately, "non-split" phenomena only occur over non-algebraically closed fields, so not all the traditional tools of classical algebraic geometry apply. Using the generalized field norm map from my talk last week, I'll describe a concrete example of a non-split torus. Then we'll try to use that example to try and understand the importance of non-split tori.
LOCATION:C517 Wells Hall
DTSTART:20191118T213000Z
DTEND:20191118T223000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20700
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20717@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Derivations on von Neumann algebras
DESCRIPTION:Speaker\: Brent Nelson, MSU\r\nIn this learning seminar style talk, I will define the notion of a derivation on a von Neumann algebra. I will also discuss their history and how they factor into modern research in operator algebras.
LOCATION:C304 Wells Hall
DTSTART:20191119T163000Z
DTEND:20191119T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20717
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20710@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Spectral sequence from Khovanov to instanton homology
DESCRIPTION:Speaker\: Matthew Hedden, MSU\r\n
LOCATION:C117 Wells Hall
DTSTART:20191119T170000Z
DTEND:20191119T183000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20710
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20708@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Applications of augmentations in contact topology
DESCRIPTION:Speaker\: Honghao Gao, MSU\r\nChekanov introduced a differential graded algebra as an invariant for Legendrian knots in standard contact manifold R^3. An augmentation is a rank 1 representation of the dga. Augmentations are accessible invariants, and the moduli space of augmentations carries important properties from both algebraic and geometric perspectives. In this talk, I will review some problems in contact topology and discuss the applications of augmentations.
LOCATION:C204A Wells Hall
DTSTART:20191119T200000Z
DTEND:20191119T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20708
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20712@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Rigidity for higher dimensional expanding maps
DESCRIPTION:Speaker\: Andrey Gogolyev, Ohio State University \r\nExpanding maps are self covers of smooth compact manifolds which expand the lengths of all non-zero tangent vectors. Classification of such maps up to topological conjugacy is known due to work of Shub, Franks and Gromov. Classification up to smooth conjugacy should be quite different because periodic points of expanding maps carry invariants of $C^1$ conjugacy. Shub and Sullivan classified expanding maps on the circle up to smooth conjugacy on the circle. I will explain smooth classification of expanding maps in higher dimensions on and open dense set in the space of expanding maps. Joint work with F. Rodriguez Hertz.
LOCATION:C304 Wells Hall
DTSTART:20191119T205000Z
DTEND:20191119T215000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20712
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20709@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:On the modularity of elliptic curves over imaginary quadratic fields
DESCRIPTION:Speaker\: Patrick Allen, UIUC\r\nThe Langlands-Tunnell theorem is an important starting point in Wiles's proof of the modularity of semistable elliptic curves over the rationals. Over imaginary quadratic fields it is unclear how to similarly use the Langlands-Tunnell theorem and Wiles's strategy runs into problems right from the start. I will motivate and explain the subtle but fundamental issues that arise, and indicate how they can be circumvented in many cases. As an application, we deduce that a positive proportion of elliptic curves over imaginary quadratic fields are modular. This is joint work with Chandrashekhar Khare and Jack Thorne.
LOCATION:C304 Wells Hall
DTSTART:20191120T200000Z
DTEND:20191120T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20709
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20690@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Learning Together Through Collaborative Research: The Case of Proof in Secondary Mathematics
DESCRIPTION:Speaker\: Michelle Cirillo, University of Delaware, Jennifer Reed, Odyssey Charter Middle School, Delaware\r\nThe Proof in Secondary Classrooms (PISC) project is a design and development research study focused on secondary students’ success with mathematical proof. The goal of this project was to develop a new and improved intervention to support the teaching and learning of proof. The central research objective of this project was to develop a pedagogical framework and a corresponding set of lesson plans and support materials to guide teachers toward improving students’ success with proof. The primary educational objective of this project was to support mathematics educators in understanding particular sub-goals of proof and developing strategies for teaching them. We present data and findings from our three-year collaboration on this project (2016-2019), which made use of ideas from design research and lesson study, and we discuss lessons learned through our collaboration.
LOCATION:252 EH
DTSTART:20191120T203000Z
DTEND:20191120T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20690
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19609@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:The graph isomorphism game for quantum graphs
DESCRIPTION:Speaker\: Kari Eifler, Texas A&M University\r\nNon-local games give us a way of observing quantum behaviour through the observation of only classical data. The graph isomorphism game is one such non-local game played by Alice and Bob which involves two finite, undirected graphs. A winning strategy for the game is called quantum if it utilizes some shared resource of quantum entanglement between the players. We say two graphs are quantum isomorphic if there is a winning quantum strategy for the graph isomorphism game. We show that the *-algebraic, C*-algebraic, and quantum commuting (qc) notions of a quantum isomorphism between classical graphs X and Y are all equivalent. This is based on joint work with M. Brannan, A. Chirvasitu, S. Harris, V. Paulsen, X. Su, and M. Wasilewski.
LOCATION:C304 Wells Hall
DTSTART:20191121T163000Z
DTEND:20191121T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19609
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20714@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Stability of traveling planewave solutions to Lorentzian vanishing mean curvature flow
DESCRIPTION:Speaker\: Leonardo Abbrescia, MSU\r\nLorentzian minimal submanifolds of Minkowski space are the dynamic analogue of minimal surfaces in the elliptic regime. They are defined by the vanishing of mean curvature, which can be expressed as a system of geometric PDEs. With the requirement that the submanifold be Lorentzian, that is, that the induced metric is Lorentzian, the equations have a hyperbolic nature. Consequently, the natural approach to study them is via the Cauchy initial value problem. In this talk we discuss stability properties of traveling planewave solutions to these equations, and highlight the difficulties introduced by the "infinite energy" planewave background. This is joint work with Willie Wong.
LOCATION:C517 Wells Hall
DTSTART:20191121T180000Z
DTEND:20191121T185000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20714
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19628@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Braid invariant relating knot Floer homology and Khovanov homology
DESCRIPTION:Speaker\: Akram Alishahi, University of Georgia\r\nKhovanov homology and knot Floer homology are two knot invariants that were defined around the same time, and despite their different constructions, share many formal similarities. After reviewing the construction of Khovanov homology and some of these similarities, we will discuss an algebraic braid invariant which is closely related to both Khovanov homology and the refinement of knot Floer homology into tangle invariants. This is a joint work with Nathan Dowlin.\r\n
LOCATION:C304 Wells Hall
DTSTART:20191121T190000Z
DTEND:20191121T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19628
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-21717@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Git/Github and Zotero Workshop
DESCRIPTION:Speaker\: Craig Gross, Rachel Domagalski, MSU\r\nThe AMS Grad Student Chapter is putting on a Git, GitHub, and Zotero workshop. If you want to know more about version control / staying organized / making .bib files / best collaboration practices, this workshop is for you! Please bring your laptop. Snacks will be provided!\r\n
LOCATION:C204 Wells Hall
DTSTART:20191121T210000Z
DTEND:20191121T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=21717
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20705@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Undergraduate MTH and STT Research Project Presentations
DESCRIPTION:Speaker\: Exchange Program and MSU Student Research Teams\r\nSpecial event: Undergraduate MTH and STT Research Project Presentations\r\n\r\nExchange Program and MSU Student Research Teams will present the results of their research projects\r\n
LOCATION:C304 Wells Hall
DTSTART:20191122T203000Z
DTEND:20191123T000000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20705
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19669@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Q-ball imaging using predicted diffusion gradient directions
DESCRIPTION:Speaker\: Yeonhyang Kim, Central Michigan University\r\nWe review the theory of q-ball imaging and describe a simple linear matrix formulation for the q-ball reconstruction based on spherical harmonic basis function interpolation. In this talk, we present a novel method to improve the q-ball reconstruction by determining appropriate positions at which a synthesized signal is obtained by combining surrounding signals in given diffusion gradient directions.
LOCATION:A203 Wells Hall
DTSTART:20191122T211000Z
DTEND:20191122T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19669
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20716@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Local rigidity for partially hyperbolic toral automorphisms
DESCRIPTION:Speaker\: Boris, Kalinin, Penn State University\r\nWe study perturbations of an irreducible ergodic toral automorphism $L$ with non-trivial center. For a small perturbation $f$ of $L$ with smooth center foliation we obtain results on regularity of the leaf conjugacy to $L$ and of a Holder topological conjugacy to $L$, when it exists. As a corollary, we show that for any symplectic perturbation a Holder conjugacy to $L$ must be smooth. For a totally irreducible $L$ with two-dimensional center, we establish various equivalent conditions that ensure smooth conjugacy between $L$ and $f$. This is joint work with Andrey Gogolev and Victoria Sadovskaya
LOCATION:C304 Wells Hall
DTSTART:20191126T205000Z
DTEND:20191126T215000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20716
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20715@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:The role of water molecules in Ketohexokinase (KHK) inhibitor design
DESCRIPTION:Speaker\: Meihua Tu, Medicine Design, Pfizer Inc.\r\nIncreased fructose consumption and its subsequent metabolism have been implicated in hepatic steatosis, dyslipidemia, obesity, and insulin resistance in humans. Since ketohexokinase (KHK) is the principal enzyme responsible for fructose metabolism, inhibition of KHK may ameliorate non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) by decreasing fructose conversion to fructose-1-phosphate. Initial low MW hits were identified by fragment screening. A combination of parallel synthesis and structure-based drug design yielded a clinic candidate, currently in clinic trials. This presentation will focus on computational techniques that have been applied in the optimization of lead compounds. In particular, how water molecule energy profile in the binding pocket was used to guide compound design. Our successful fragment-to-candidate story will demonstrate the power of combining structure-based drug design with parallel chem.
LOCATION:C304 Wells Hall
DTSTART:20191202T150000Z
DTEND:20191202T160000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20715
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19661@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:An Introduction to Link Invariants from Tangle Operators
DESCRIPTION:Speaker\: Sanjay Kumar, MSU\r\nIn the early 90’s, Reshetikhin and Turaev constructed topological invariants of 3-manifoolds and of framed links in 3-manifolds using quantum groups. In this talk, I will introduce their approach with specific examples and show how they relate to known link invariants such as the Jones polynomial.
LOCATION:C304 Wells Hall
DTSTART:20191202T200000Z
DTEND:20191202T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19661
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-21718@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Spectral sequences in Floer theory (ctd)
DESCRIPTION:Speaker\: Matt Hedden, MSU\r\nTalk continued from 2 weeks prior
LOCATION:C117 Wells Hall
DTSTART:20191203T170000Z
DTEND:20191203T183000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=21718
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19621@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Pure braids and link concordance
DESCRIPTION:Speaker\: Shelly Harvey, Rice\r\nIf one considers the set of m-component based links in R^3\r\nwith a 4-dimensional equivalence relationship on it, called\r\nconcordance, one can form a group called the link concordance group,\r\nC^m. Questions in concordance are important in for classification\r\nquestions in topological and smooth 4-manifolds It is well known that\r\nthe link concordance group contains the isotopy class of pure braid\r\nwith m strands, P_m. That is, two braids are concordant if and only\r\nif they are isotopic! In the late 90's Tim Cochran, Kent Orr, and\r\nPeter Teichner defined a filtration of the knot/link concordance group\r\ncalled the n-solvable filtration. This filtration gives a way to\r\napproximate whether a link is trivial in the group. We discuss the\r\nrelationship between pure braids and the n-solvable filtration as well\r\nas various other more geometrically defined filtrations coming from\r\ngropes and Whitney towers. This is joint work with Aru Ray and Jung\r\nHwan Park.
LOCATION:C304 Wells Hall
DTSTART:20191205T190000Z
DTEND:20191205T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19621
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-19668@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Local Existence and Blow-Up For SQG Patches
DESCRIPTION:Speaker\: Neel Patel, University of Michigan\r\nThe two-dimensional surface quasi-geostrophic (SQG) equation is a model for atmospheric or oceanic flows and has strong structural similarity with the 3D Euler equation. Interpolating be-tween the 2D Euler equation and the 2D SQG equation, one obtains the one-parameter $0\leq\alpha\leq1$ family of generalized SQG (gSQG) equations. The problem of wellposedness or finite time singularity for the gSQG equations is considered, with the aim of resolving this question for the 2D SQG equation $\alpha=1$. Recently, patch solutions that become singular in finite time have been constructed for a subfamily of the gSQG equations in the half-plane setting. We discuss this result and also discuss a blow-up criterion of lower regularity than suggested by numerics.
LOCATION:A203 Wells Hall
DTSTART:20191206T211000Z
DTEND:20191206T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19668
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-20691@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Price Inequalities and Benjamini-Schramm Convergence
DESCRIPTION:Speaker\: Luca Di Cerbo, University of Florida\r\nIn this talk, I will present a study of Betti numbers of sequences of compact negatively curved Riemannian manifolds Benjamini-Schramm converging to their universal covers. The main tools are a Price inequality for harmonic forms on negatively curved spaces, and an effective thick-thin decomposition.
LOCATION:C304 Wells Hall
DTSTART:20191210T160000Z
DTEND:20191210T170000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=20691
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-21723@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:Smooth 4-manifolds and the geometry of 3-manifolds
DESCRIPTION:Speaker\: Matthew Stoffregen, Massachusetts Institute of Technology\r\nOne of the interests of low-dimensional topologists is understanding which smooth 4-manifolds can bound a given 3-manifold, or, as a special case, understanding the set of 3-manifolds up to so-called homology cobordism (to be defined in the talk). This question turns out to have applications to the study of triangulations of high-dimensional manifolds, and is a natural proving ground for Floer-theoretic techniques of studying 3-manifolds. In this talk, we will give some structure theorems about the homology cobordism group, and show that there are three-manifolds that are very far from having any of the seven non-hyperbolic Thurston geometries. This talk includes joint work with I. Dai, K. Hendricks, J. Hom, L. Truong, and I. Zemke.
LOCATION:C304 Wells Hall
DTSTART:20191210T211000Z
DTEND:20191210T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=21723
END:VEVENT
BEGIN:VEVENT
UID:20191214T162846-21721@math.msu.edu
DTSTAMP:20191214T162846Z
SUMMARY:In and around stable homotopy groups of spheres
DESCRIPTION:Speaker\: Zhouli Xu, Massachusetts Institute of Technology\r\nThe computation of stable homotopy groups of spheres is one of the most fundamental problems in topology. Despite its simple definition, it is notoriously hard to compute. It has connections to many areas of mathematics. In this talk, I will discuss a recent breakthrough on this problem, which depends on motivic homotopy theory in a critical way. I will also talk about applications to smooth structures on spheres, and towards the open problem of Kervaire invariant one in dimension 126. This talk is based on several joint work with Bogdan Gheorghe, Daniel Isaksen, and Guozhen Wang.
LOCATION:C304 Wells Hall
DTSTART:20191212T211000Z
DTEND:20191212T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=21721
END:VEVENT
END:VCALENDAR