Long time inviscid damping near Couette in Sobolev spaces

Abstract

We give an elementary proof of long time inviscid damping for Sobolev perturbations near the Couette flow $(y,0)$ for the 2D Euler equations on $\mathbb{T} \times \mathbb{R}$. For any $s>1$ and any initial vorticity perturbation of size $O(\epsilon)$ in $H^s$, we obtain velocity damping estimates up to a time scale $ t = O(\epsilon^{-\delta_s} )$, where $\delta_s=1/3$ when $s\to 1+$ and $\delta_s=1/2$ for $s>2$.