Ill-posedness and inviscid limit of basic equations of fluid dynamics in Besov spaces
Jinlu Li, Xing Wu, Yanghai Yu
TL;DR
This paper analyzes ill-posedness and inviscid-limit behavior for the Euler, Navier-Stokes, and surface quasi-geostrophic equations in Besov spaces on the torus. By constructing explicit high-frequency traveling-wave data via lacunary Fourier series, it proves ill-posedness of the data-to-solution map in $B^s_{p,\infty}$ for the Euler and QG equations and shows non-Hölder time regularity of the Euler flow in these spaces. It also demonstrates non-convergence of the vanishing viscosity limit from Navier–Stokes to Euler in the same Besov scale, and establishes analogous ill-posedness and non-convergence results for the dissipative and inviscid QG equations, using dyadic analysis and precise frequency-localized constructions. Overall, the work extends endpoint ill-posedness results to broader Besov settings and clarifies the delicate inviscid-limit behavior in critical Besov spaces.
Abstract
In this paper, we consider the Cauchy problem to the basic equations of fluid dynamics on the torus. Firstly, we construct a new initial data and provide a simple proof on the ill-posedness of $B^s_{p,\infty}$ solution of the Euler equations and the surface quasi-geostrophic equation, which covers the results obtained by Cheskidov-Shvydkoy \cite{CS} and Misiołek-Yoneda \cite{MY}. Secondly, we prove the failure of the $B^s_{p,\infty}$-convergence in the inviscid limit for both the Navier-Stokes equations and the surface quasi-geostrophic equation.
