On Liouville type theorems in the stationary non-Newtonian fluids

Abstract

In this paper we prove a Liouville type theorem for the stationary equations of a non-Newtonian fluid in $\mathbb{R}^3$ with the viscous part of the stress tensor $\mathbf{A}_p(u) = \mathrm{div} ( | \mathbf{D}(u) |^{p-2} \mathbf{D}(u) )$, where $\mathbf{D}(u) = \frac 12 ( \nabla u + ( \nabla u )^{\top})$ and $\frac 95 < p < 3$. We consider a weak solution $u \in W^{1,p}_{loc}(\mathbb{R}^3)$ and its potential function $\mathbf{V} = (V_{ij}) \in W^{2,p}_{loc}(\mathbb{R}^3)$, i.e. $\nabla \cdot \mathbf{V} = u$. We show that there exists a constant $s_0=s_0(p)$ such that if the $L^s$ mean oscillation of $\mathbf{V}$ for $s>s_0$ satisfies a certain growth condition at infinity, then the velocity field vanishes. Our result includes the previous results \cite{CW20, CW19} as particular cases.