analysis math-physics

The nonlinear stability of the Schwarzschild metric without symmetry

Mihalis Dafermos
Princeton University
December 6, 2019

I will discuss an upcoming result proving the full finite-codimension non-linear asymptotic stability of the Schwarzschild family as solutions to the Einstein vacuum equations in the exterior of the black hole region. 


No symmetry is assumed. The work is based on our previous understanding of linear stability of Schwarzschild in double null gauge. Joint work with G. Holzegel, I. Rodnianski and M. Taylor.

Unitary, Symplectic, and Orthogonal Moments of Moments

Emma Bailey
University of Bristol
November 15, 2019

The study of random matrix moments of moments has connections to number theory, combinatorics, and log-correlated fields. Our results give the leading order of these functions for integer moments parameters by exploiting connections with Gelfand-Tsetlin patterns and counts of lattice points in convex sets. This is joint work with Jon Keating and Theo Assiotis. 

Billiards and Hodge theory

Simion Filip
Harvard University
April 19, 2017
A polygon with rational angles can be unfolded and glued into a finite genus Riemann surface equipped with a flat metric and some singularities. The moduli space of all such structures carries an action of the group $\mathrm{PSL}(2,\mathbb R)$ and this can be viewed as a renormalization of the billiard flow in the initial polygon. After introducing the basics, I will explain how Hodge theory can give information on the $\mathrm{PSL}(2,\mathbb R)$ dynamics, in particular on the Lyapunov exponents and orbit closures.

Thermodynamical approach to the Markoff-Hurwitz equation

Michael Magee
Yale University
April 19, 2017
I'll first introduce the Markoff-Hurwitz equation and explain how it plays a fundamental role in different areas of mathematics. The main result I'll discuss is a true asymptotic formula for the number of real points in a fixed orbit of the automorphism group of the Markoff-Hurwitz variety with bounded maximal entry. In particular this establishes an asymptotic count for the number of integer solutions to the Markoff-Hurwitz equation of bounded height.

Soliton resolution for energy critical wave and wave map equations

Hao Jia
Member, School of Mathematics
April 12, 2017
It is widely believed that the generic dynamics of nonlinear dispersive equations in the whole space is described by solitary waves and linear dispersions. More precisely, over large times, solutions tend to de-couple into solitary waves plus radiation. It remains an open problem to rigorously establish such a description for most dispersive equations. For energy critical wave equations in the radial case, we have better understanding, using tools such as ``channel of energy inequalities" firstly introduced by Duyckaerts-Kenig-Merle, and monotonicity formulae.