35 research outputs found
From the Hartree equation to the Vlasov-Poisson system: strong convergence for a class of mixed states
We consider the evolution of fermions interacting through a Coulomb or
gravitational potential in the mean-field limit as governed by the nonlinear
Hartree equation with Coulomb or gravitational interaction. In the limit of
large , we study the convergence in trace norm towards the classical
Vlasov-Poisson equation for a special class of mixed quasi-free states.Comment: 21 pages. Typos corrected, references updated and detailed proof of
Lemma 2.4 adde
From microscopic dynamics to kinetic equations
Starting from a system of N particles at a microscopic scale, we describe different scaling limits which lead to kinetic equations in a macroscopic regime: the low-density limit, the weak-coupling limit, the grazing collision limit and the mean-field limit. A particular relevance is given to the rigorous derivation of the Boltzmann equation (starting from a system of N particles interacting via a short range potential) and to a consistency result concerning the Landau equation. A Kac's model for the Landau equation is presented as well. The last part of the work is dedicated to the Vlasov-Poisson system, in particular we discuss the Cauchy problem related to this equation in presence of a point charge
On the validity of the Boltzmann equation for short range potentials
We consider a classical system of point particles interacting by means of a
short range potential. We prove that, in the low--density (Boltzmann--Grad)
limit, the system behaves, for short times, as predicted by the associated
Boltzmann equation. This is a revisitation and an extension of the thesis of
King (unpublished), appeared after the well known result of Lanford for hard
spheres, and of a recent paper by Gallagher et al (arXiv: 1208.5753v1). Our
analysis applies to any stable and smooth potential. In the case of repulsive
potentials (with no attractive parts), we estimate explicitly the rate of
convergence
Polynomial propagation of moments and global existence for a Vlasov-Poisson system with a point charge
In this paper, we extend to the case of initial data constituted of a Dirac
mass plus a bounded density (with finite moments) the theory of Lions and
Perthame [6] for the Vlasov-Poisson equation. Our techniques also provide
polynomially growing in time estimates for moments of the bounded density.Comment: 27 pages; new version: few typos have been corrected, the
introduction has been modifie