Events for 02/11/2022 from all calendars

Working Seminar on Banach and Metric Spaces

Time: 10:00AM - 11:30AM

Location: BLOC 302

Speaker: Chris Gartland, Texas A&M University

Title: Heisenberg group

Noncommutative Geometry Seminar

Time: 2:00PM - 3:00PM

Location: ZOOM

Speaker: Zhizhang Xie, Texas A&M University

Title: On Gromov’s Dihedral extremality and rigidity conjectures

Abstract: In this talk, I will present my recent joint work with Jinmin Wang and Guoliang Yu on Gromov’s dihedral extremality and rigidity conjectures. These two conjectures of Gromov concern comparisons of scalar curvature, mean curvature and dihedral angles for compact manifolds with corners, which can be viewed as scalar curvature analogues of the Alexandrov’s triangle comparisons for spaces whose sectional curvature is bounded below. Gromov’s conjectures have profound implications in geometry and mathematical physics such as the positive mass theorem. In our recent work, by using Dirac operator methods, we answer positively Gromov’s dihedral extremality conjecture for convex polyhedra in all dimensions, and Gromov’s dihedral rigidity conjecture for convex polyhedra in dimension three.

URL: Event link

Algebra and Combinatorics Seminar

Time: 3:00PM - 4:00PM

Location: Zoom

Speaker: Ryan Martin, Iowa State University

Title: Counting paths, cycles, and other subgraphs in planar graphs

Abstract: For a planar graph H, let N_P(n,H) denote the maximum number of copies of H in an n-vertex planar graph. The case where H is the path on 3 vertices, H=P_3, was established by Alon and Caro. The case of H=P_4 was determined, also exactly, by Gy\H{o}ri, Paulos, Salia, Tompkins, and Zamora. In this talk, we will give the asymptotic values for H equal to P_5 and P_7 as well as the cycles C_6, C_8, C_{10} and C_{12} and discuss the general approach which can be used to compute the asymptotic value for many other graphs H.