Local Hadamard well-posedness results for the Navier-Stokes equations

TL;DR

This paper establishes local well-posedness for the 3D Navier-Stokes equations with initial data in specific function spaces, showing continuous dependence on initial conditions without requiring smallness assumptions.

Contribution

It introduces new conditions on initial data in $VMO^{-1}$ spaces that guarantee local well-posedness and continuous dependence for weak solutions, extending previous results.

Findings

Dependence of solutions on initial data in $VMO^{-1}$ spaces

Extension of well-posedness results beyond small data regimes

Persistence of regularity without perturbative assumptions

Abstract

In this paper we consider classes of initial data that ensure local-in-time Hadamard well-posedness of the associated weak Leray-Hopf solutions of the three-dimensional Navier-Stokes equations. In particular, for any solenodial $L_{2}$ initial data $u_{0}$ belonging to certain subsets of $VMO^{-1}(\mathbb{R}^3)$, we show that weak Leray-Hopf solutions depend continuously with respect to small divergence-free $L_{2}$ perturbations of the initial data $u_{0}$ (on some finite-time interval). Our main result is inspired and improves upon previous work of the author \cite{barker2018} and work of Jean-Yves Chemin \cite{chemin}. Our method builds upon \cite{barker2018} and \cite{chemin}. In particular our method hinges on decomposition results for the initial data inspired by Calder\'{o}n \cite{Calderon90} together with use of persistence of regularity results. The persistence of regularity statement presented may be of independent interest, since it does not rely upon the solution or the initial data being in the perturbative regime.