BEGIN:VCALENDAR
VERSION:2.0
PRODID:Mathematics Seminar Calendar
BEGIN:VEVENT
UID:20191021T085715-18593@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19616@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19605@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19603@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19602@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19615@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18596@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19623@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19620@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19613@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19617@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19624@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-17489@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19606@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19635@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19625@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19610@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19634@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19636@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19642@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19607@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18587@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19637@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19631@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19651@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19647@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19644@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19650@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19608@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19649@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18580@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19662@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19612@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19663@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19667@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19646@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19664@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18586@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19653@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19671@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19674@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19679@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19675@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19681@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19670@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18597@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19633@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19654@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19614@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19680@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-20682@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19677@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19632@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18588@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19626@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19683@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19655@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-20683@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19629@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-20684@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-20686@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19676@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19638@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19641@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18600@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19656@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBD
DESCRIPTION:Speaker\: Dongsoo Lee, MSU\r\nTBD
LOCATION:C304 Wells Hall
DTSTART:20191028T190000Z
DTEND:20191028T195000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19656
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19673@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Olga Turanova, MSU\r\nIn collaboration with the AWM Student Chapter, we are most happy to welcome Professor Turanova to MSU! She will be giving a colloquium talk on a topic TBA.
LOCATION:C304 Wells Hall
DTSTART:20191028T200000Z
DTEND:20191028T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19673
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19630@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-20685@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19678@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19619@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-18589@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19657@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBD
DESCRIPTION:Speaker\: Gorapada Bera, MSU\r\nTBD
LOCATION:C304 Wells Hall
DTSTART:20191104T200000Z
DTEND:20191104T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19657
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19672@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19648@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBD
DESCRIPTION:Speaker\: Dan Rutherford, Ball State University\r\n
LOCATION:C204A Wells Hall
DTSTART:20191105T200000Z
DTEND:20191105T210000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19648
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19645@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Ioakeim Ampatzoglou, University of Texas, Austin\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20191106T211000Z
DTEND:20191106T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19645
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19639@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Charles Smart, U Chicago\r\n
LOCATION:C304 Wells Hall
DTSTART:20191107T163000Z
DTEND:20191107T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19639
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19643@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Kritika Singhal, Ohio State University\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:20191021T085715-19658@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBD
DESCRIPTION:Speaker\: Wenchuan Tian, MSU\r\nTBD
LOCATION:C304 Wells Hall
DTSTART:20191111T200000Z
DTEND:20191111T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19658
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19622@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Peter Lambert-Cole, Max Planck Institute for Mathematics\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20191114T190000Z
DTEND:20191114T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19622
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19618@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Marius Lemm, Harvard\r\n
LOCATION:C304 Wells Hall
DTSTART:20191115T153000Z
DTEND:20191115T163000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19618
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19640@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Yao Yao, Georgia Tech\r\n
LOCATION:C304 Wells Hall
DTSTART:20191115T211000Z
DTEND:20191115T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19640
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19659@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBD
DESCRIPTION:Speaker\: Sarah Klanderman, MSU\r\nTBD
LOCATION:C304 Wells Hall
DTSTART:20191118T200000Z
DTEND:20191118T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19659
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19609@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Kari Eifler, Texas A&M University\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20191121T163000Z
DTEND:20191121T173000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19609
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19628@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Akram Alishahi, University of Georgia\r\nTBA
LOCATION:C304 Wells Hall
DTSTART:20191121T190000Z
DTEND:20191121T200000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19628
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19669@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Yeonhyang Kim, Central Michigan University\r\n
LOCATION:A203 Wells Hall
DTSTART:20191122T211000Z
DTEND:20191122T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19669
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19660@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBD
DESCRIPTION:Speaker\: Hitesh Gakhar, MSU\r\nTBD
LOCATION:C304 Wells Hall
DTSTART:20191125T200000Z
DTEND:20191125T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19660
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19661@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBD
DESCRIPTION:Speaker\: Sanjay Kumar, MSU\r\nTBD
LOCATION:C304 Wells Hall
DTSTART:20191202T200000Z
DTEND:20191202T205000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19661
END:VEVENT
BEGIN:VEVENT
UID:20191021T085715-19621@math.msu.edu
DTSTAMP:20191021T085715Z
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:20191021T085715-19668@math.msu.edu
DTSTAMP:20191021T085715Z
SUMMARY:TBA
DESCRIPTION:Speaker\: Neel Patel, University of Michigan\r\n
LOCATION:A203 Wells Hall
DTSTART:20191206T211000Z
DTEND:20191206T220000Z
URL:https://math.msu.edu/Seminars/TalkView.aspx?talk=19668
END:VEVENT
END:VCALENDAR