A sharp time-weighted inequality for the compressible Navier-Stokes-Poisson system in the critical $L^{p}$ framework

TL;DR

This paper establishes a sharp time-weighted inequality for the global strong solutions of the compressible Navier-Stokes-Poisson system in critical $L^{p}$ Besov spaces, revealing faster density decay compared to velocity.

Contribution

It introduces a novel regularity assumption for low frequencies and derives optimal decay estimates, highlighting differences from standard Navier-Stokes behavior.

Findings

Density decays faster than velocity at half the rate.

Established sharp time-weighted inequalities for solutions.

Utilized non-classical Besov product estimates and Sobolev embeddings.

Abstract

The compressible Navier-Stokes-Poisson system takes the form of usual Navier-Stokes equations coupled with the self-consistent Poisson equation, which is used to simulate the transport of charged particles under the electric field of electrostatic potential force. In this paper, we focus on the large time behavior of global strong solutions in the $L^{p}$ Besov spaces of critical regularity. By exploring the dissipative effect arising from Poisson potential, we posed the new regularity assumption of low frequencies and then establish a \textit{sharp} time-weighted inequality, which leads to the optimal time-decay estimates of the solution. Indeed, we see that the decay of density is faster at the half rate than that of velocity, which is a different ingredient in comparison with the situation of usual Navier-Stokes equations. Our proof mainly depends on tricky and non classical Besov product estimates with respect to various Sobolev embeddings.