A Brief Introduction to Gödel's Incompleteness Theorems In 1931 Kurt Gödel proved a pair of landmark results that limited the strength of formal theories of mathematics. These "incompleteness theorems" are central to modern understandings of logic, and also to numerous misunderstandings. So today, we'll explore these theorems - how they work, how they were developed […]
Title: Soap films, Plateau's laws, and the Allen-Cahn equation Abstract: Plateau's problem of minimizing area among surfaces with a common boundary is the basic model for soap films and leads to the theory of minimal surfaces. In this talk we will discuss a modification of Plateau's problem in which surfaces are replaced with regions of small […]
Title:Â Finite approximations as a tool for studying triangulated categories.Abstract:Â A metric on a category assigns lengths to morphisms, with the triangle inequality holding. This notion goes back to a 1974 article by Lawvere. We'll start with a quick review of some basic constructions, like forming the Cauchy completion of a category with respect to a metric.And […]
Title: On an application of the residue method. Abstract: When a period integral of an automorphic form converges and is not zero it is often related to a special value of an L-function and indicates that the automorphic form is a functorial transfer. When convergence fails it is still interesting to make sense of the […]
Title: First eigenvalue estimates on asymptotically hyperbolic manifolds and their submanifolds.  Abstract: I will report on joint work with Samuel Pérez-Ayala. We derive a sharp upper bound for the first eigenvalue $lambda_{1,p}$ of the $p$-Laplacian on asymptotically hyperbolic manifolds for $1<p<infty$. We then prove that a particular class of conformally compact submanifolds within asymptotically hyperbolic […]
Title: The simply typed 2λ-calculus Abstract: 2λ-calculus is a language with three levels: types, terms, and rewrites. I will explore their properties and give categorical description of the equational theory on the rewrites of the 2λ-calculus
From Stochastic to Deterministic: SGD dynamics of non-convex models in high dimensionsStochastic gradient descent (SGD) stands as a cornerstone of optimization and modern machine learning. However, understanding why SGD performs so well remains a major challenge. In this talk, I will present a theory for SGD in high dimensions when the number of samples and […]
Title: Discrete Series and Infinitesimal Characters Abstract: The infinitesimal character is an important invariant of an irreducible representation of a real group. We expect particularly nice representations of the group will have particularly nice infinitesimal character. We'll first introduce the definition of the infinitesimal character. Then, we discuss a recent application found by Krotz, Kuit, […]
Title: Recovery of time-dependent coefficients in hyperbolic equations on Riemannian manifolds from partial data.Abstract: In this talk we discuss inverse problems of determining time-dependent coefficients appearing in the wave equation in a compact Riemannian manifold of dimension three or higher. More specifically, we are concerned with the case of conformally transversally anisotropic manifolds, or in […]
Title:Â Properties of log canonical singularities in positive characteristic.Abstract:Â We will investigate if some well known properties of log canonical singularities over the complex numbers still hold true over perfect fields of positive characteristic and over excellent rings with perfect residue fields. We will discuss both pathological behavior in characteristic p as well as some positive results […]
Title: Covers of P^1 and number fields Abstract:Â Let $n$ be an integer. Via the Minkowski embedding, an order $mathcal{O}$ in a degree $n$ number field can be seen as a lattice. Similarly, given a degree $n$ cover of $mathbb{P}^1$, the pushforward of the structure sheaf is an interesting rank $n$ vector bundle on $mathbb{P^1}$. […]
Title:Â A Hodge-theoretic proof of Hwang's theoremAbstract:Â I will explain a Hodge-theoretic proof for Hwang's theorem, which says that if the base of a Lagrangian fibration on an irreducible holomorphic symplectic manifold is smooth, then it must be projective space. The result is contained in a joint paper with Ben Bakker from last fall.
Title: On the Harish-Chandra regularity theorem Abstract: The Harish-Chandra regularity theorem roughly says that an invariant eigendistribution on a semisimple Lie group is represented by some locally integrable function. We shall explain the proof of this theorem with an emphasis on the case of SL(2).
Title: Exotic spheres from p-adic cohomology theories.Abstract:Part 1: An n-dimensional exotic sphere is a smooth manifold homeomorphic, but not diffeomorphic, to S^n. I will give a leisurely introduction to the telescope conjecture in stable homotopy theory (recently resolved in joint work with Burklund, Levy, and Schlank), by explaining its implications for the diffeomorphism classification of […]
Title: Finiteness for Hecke algebras of p-adic reductive groups. Abstract: Part 1: Let F be a p-adic field, and G the F-points of a reductive group over F. For any compact open subgroup U of F, one can form the Hecke algebra C of complex valued functions on G, invariant under left and right translation by […]
Title: Singularities in Mixed Characteristic via Alterations.Abstract:Â Multiplier ideals and test ideals are ways to measure singularities in characteristic zero and p > 0 respectively. In characteristic zero, multiplier ideals are computed by a sufficiently large blowup by comparing the canonical module of the base and the resolution. In characteristic p > 0, test ideals were […]
Title: A Geometric Introduction to Representation TheoryAbstract: What exactly does it mean for a group to represent the symmetries of an object? In this talk, I will attempt to answer this question by convincing you that the study of group actions, or representations, comes up even more naturally than the study of groups themselves. We […]
Title: A family of Kahler flying wing steady Ricci solitonsAbstract: Steady Kahler-Ricci solitons are eternal solutions of the Kahler-Ricci flow. I will present new examples of such solitons with strictly positive sectional curvature that live on C^n and provide an answer to an open question of H.-D. Cao in complex dimension n>2. This is joint […]
Title: Syzygies of adjoint linear series on projective varietiesAbstract: Syzygies of algebraic varieties have long been a topic of intense interest among algebraists and geometers alike. Starting with the pioneering work of Mark Green on curves, numerous attempts have been made to extend these results to higher dimensions. Ein and Lazarsfeld proved that if A is a very ample […]
Title: Kloosterman sums in representation theory of GL(n, Fq) Abstract: Given a "nice" irreducible representation of GL(n, Fq), one can define a special matrix coefficient attached to it, called the Bessel function. Often Kloosterman sums show up as special values of these Bessel functions. In this talk, I will first explain my previous results regarding […]