Late-time asymptotics of small data solutions for the Vlasov-Poisson system

TL;DR

This paper analyzes the long-term behavior of small data solutions to the Vlasov-Poisson system in three dimensions, revealing self-similar expansions, modified scattering, and convergence properties of the distribution function.

Contribution

It provides the first detailed description of late-time asymptotics, including self-similar expansions and enhanced scattering results, for the Vlasov-Poisson system with small initial data.

Findings

Spatial density and force field exhibit asymptotic self-similar expansions.

Distribution function converges to a regular distribution with arbitrary rate.

Distribution function weakly converges to a Dirac mass on zero velocity set.

Abstract

In this paper, we study the precise late-time asymptotic behaviour of small data solutions for the Vlasov-Poisson system in dimension three. First, we show that the spatial density and the force field satisfy asymptotic self-similar polyhomogeneous expansions. Moreover, we obtain an enhanced modified scattering result for this non-linear system. We show that the distribution function converges, with an arbitrary rate, to a regular distribution function along high order modifications to the characteristics of the linearised problem. We exploit a hierarchy of asymptotic conservation laws for the distribution function. As an application, we show late-time tails for the spatial density and the force field, where the coefficients in the tails are obtained in terms of the scattering state. Finally, we prove that the distribution function (up to normalisation) converges weakly to a Dirac mass on the zero velocity set.