Sharp Asymptotics for KPP Pulsating Front Speed-up and Diffusion Enhancement by Flows

Abstract

We study KPP pulsating front speed-up and effective diffusivity enhancement by general periodic incompressible flows. We prove the existence of and determine the limits $c^{\ast }(A)/A$ and $D(A)/A^2$ as $A\to \infty$, where $c^{\ast }(A)$ is the minimal front speed and $D(A)$ the effective diffusivity.

11pp