|Date: Tuesday, April 14, 2009
Title: The rate of change of width under flows
Abstract: I will discuss a geometric invariant, that we call the width, of
a manifold and first show how it can be realized as the sum of areas of
minimal 2-spheres. When $M$ is a homotopy 3-sphere, the width is loosely
speaking the area of the smallest 2-sphere needed to ``pull over'' $M$.
Second, we will estimate the rate of change of width under various geometric
Flows, including the Ricci flow and mean curvature flow, to prove sharp
estimates for extinction times. This is joint work
with Toby Colding.
Speaker: Bill Minicozzi
Institution: Johns Hopkins University