Remarks on the Liouville type problem in the stationary 3D Navier-Stokes equations

Abstract

We study the Liouville type problem for the stationary 3D Navier-Stokes equations on $\Bbb R^3$. Specifically, we prove that if $v$ is a smooth solution to (NS) satisfying $\omega={\rm curl}\,v \in L^q (\Bbb R^3) $ for some $\frac32 \leq q< 3$, and $|v(x)|\to 0$ as $|x|\to +\infty$, then either $v=0$ on $\Bbb R^3$, or $\int_{\Bbb R^6} \Phi_+ dxdy=\int_{\Bbb R^6} \Phi_- dxdy=+\infty$, where $\Phi(x,y) :=\frac{1}{4\pi}\frac{\omega (x)\cdot(x-y)\times (v(y)\times \omega(y) )}{|x-y|^3} $, and $\Phi_\pm:=\max\{ 0, \pm \Phi\}$. The proof uses crucially the structure of nonlinear term of the equations.