Uniqueness and stability of traveling vortex pairs for the incompressible Euler equation

Abstract

In this paper, we establish the uniqueness and nonlinear stability of concentrated symmetric traveling vortex patch-pairs for the 2D Euler equation. We also prove the uniqueness of concentrated rotating polygons as well. The proofs are achieved by a combination of the local Pohozaev identity, a detailed description of asymptotic behaviors of the solutions and some symmetry properties obtained by the method of moving planes.