EVENT DETAILS AND ABSTRACT

Title: Geodesics on S^2 and Annulus Homeomorphisms
Speaker: David Richeson
Speaker Info: Northwestern University
Brief Description:
Special Note:
Abstract:

This talk is intended for general audience. One can ask, given the 2-sphere and a Riemannian metric on that sphere, how many closed geodesics exist? Birkhoff noticed that in many cases the problem can be reduced to finding periodic points of an annulus homeomorphism. In 1992 Franks used this annulus map to prove that for any Riemannian metric on S^2, there are an infinite number of closed geodesics. In this talk we present these arguments.