Applied Math Seminar
Spring Quarter 2008
3:15 p.m.
Sloan Mathematics Corner
Building 380, Room 380-C


Friday, April 25, 2008

Lenya Ryzhik
Mathematics Department
University of Chicago

How an incompressible flow helps diffusion to mix things


Abstract:

I will describe some recent results that concern various aspects of the mixing properties of a strong incompressible flow acting together with a diffusion. In particular, we will discuss the short-time decay of solutions of the corresponding initial value problem, asymptotics of the principle Dirichlet eigenvalue and the behavior of the explosion threshold in the Zeldovich problem when the incompressible flow is strong. When the flow is prescribed, the "enhancement" of these characteristics comes from the geometric properties of the flow. We will also show that flows arising from the Stokes-Bousisnesq problems possess these "enhancement" features.