January 11, 2023 @ 4:00 pm

Skye 284

Qing Han, University of Notre Dame
Abstract: In many important geometric PDEs, solutions are not necessarily regular. When the singularity occurs, we still intend to explore whether solutions possess regularity of a certain degree. The structure of the singular sets, where solutions become singular, play an important role. In…

January 10, 2023 @ 4:00 pm

Skye 268

Corey Bregman, University of Southern Maine
Abstract: Given a geometric or algebraic structure, a moduli space can be used to study its automorphisms. In this talk, we consider two instances of such moduli spaces. In the first case, we examine automorphisms of right-angled Artin groups (RAAGs), a natural class of groups…

January 09, 2023 @ 4:00 pm

Skye 268

Zahra Aminzare, University of Iowa
Abstract: Synchronization refers broadly to patterns of coordinated behaviors that emerge spontaneously or by design in natural and artificial complex network systems. Network synchronization can arise from the dynamics of the isolated individuals, exogenous control inputs, the properties of the…

November 16, 2022 @ 4:00 pm

Zoom

Jiaping Wang, U. Minnesota
Abstract: The classical de Rham-Hodge theory implies that each cohomology class of a compact manifold is uniquely represented by a harmonic form, signifying the important role of Laplacian in geometry. The talk aims to explain some results concerning the size and structure of its spectrum. After a brief…

November 09, 2022 @ 4:00 pm

Skye 284

Jiaping Wang, U. Minnesota
Abstract: The entropy rate of a stationary sequence of random symbols was introduced by Shannon in his foundational work on information theory in 1948. In the early 1950s, Kolmogorov and Sinai realized that they could turn this quantity into an isomorphism invariant for measure-preserving…

October 26, 2022 @ 4:00 pm

Zoom

Dr. Guofang Wei, UCSB
Abstract: It is of general interest to study the difference between Ricci and sectional curvature lower bound. A well known difference is their control on Betti numbers. Recently, joint with J. Pan, we constructed manifolds/singular spaces with nonnegative Ricci curvature which give negative answers to two…

October 19, 2022 @ 4:00 pm

Skye 284

Dr. Zhiqin Lu, UC Irvine
Abstract: In this talk, we present the proof of the following theorem: let M be a complete non-compact Riemannian manifold whose curvature goes to zero at infinity, then its essential spectrum of the Laplacian on differential forms is a connected set. In particular, we study the case of form spectrum when…

June 01, 2022 @ 12:00 pm

Zoom

Spatial Ecology & Singularly Perturbed Reaction-Diffusion Equations
Prof. Arjen Doelman, Mathematisch Instituut, Lorentz Center; Leiden University, The Netherlands
Abstract: Pattern formation in ecological systems is driven by counteracting feedback mechanisms on widely different spatial scales. Moreover, ecosystem models…

May 25, 2022 @ 3:30 pm

Skye 284

M. Susan Montgomery, USC
Orthogonal representations: from groups to Hopd algebras to tensor categories
Let G be a finite group and V a finite dimensional representation of G over the complex numbers. According to a wonderful theorem of Frobenius and Schur from 1906, there are only three possibilities for V:
V has a non-…

May 18, 2022 @ 12:00 pm

Skye Hall 268

Catherine Searle, Wichita State University
Positively curved manifolds are notoriously hard to classify. In the early 90's, based on the observation that the few known examples are all highly symmetric, Karsten Grove proposed his "Symmetry Program" which suggests trying to classify such manifolds with the additional hypothesis of…

Let us help you with your search