Uniqueness and stability of entropy shocks to the isentropic Euler system in a class of inviscid limits from a large family of Navier–Stokes systems

• Published in: Inventiones mathematicae Vol. 224; no. 1; pp. 55 - 146
• Main Authors: Kang, Moon-Jin, Vasseur, Alexis F.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2021; Springer Nature B.V
• Subjects: Entropy; Fluid dynamics; Fluid flow; Mathematics; Mathematics and Statistics; Navier-Stokes equations; Perturbation; Shallow water equations; Stability; Topology; Uniqueness; Viscosity; 35B35; 76N15; 35Q30
• ISSN: 0020-9910; 1432-1297
• DOI: 10.1007/s00222-020-01004-2

We prove the uniqueness and stability of entropy shocks to the isentropic Euler systems among all vanishing viscosity limits of solutions to associated Navier–Stokes systems. To take into account the vanishing viscosity limit, we show a contraction property for any large perturbations of viscous shocks to the Navier–Stokes system. The contraction estimate does not depend on the strength of the viscosity. This provides a good control on the inviscid limit process. We prove that, for any initial value, there exist a vanishing viscosity limit to solutions of the Navier–Stokes system. The convergence holds in a weak topology. However, this limit satisfies some stability estimates measured by the relative entropy with respect to an entropy shock. In particular, our result provides the uniqueness of entropy shocks to the shallow water equation in a class of inviscid limits of solutions to the viscous shallow water equations.