A rigorous derivation of the Hamiltonian structure for the Vlasov equation

TL;DR

This paper rigorously derives the Hamiltonian structure of the Vlasov equation from the many-body Newtonian system, establishing a solid theoretical foundation for its Lie-Poisson bracket and Hamiltonian functional.

Contribution

It provides the first rigorous derivation of the Hamiltonian structure of the Vlasov equation directly from the many-body problem.

Findings

Derived the Hamiltonian functional from many-body dynamics

Established the Lie-Poisson bracket structure for Vlasov

Resolved a longstanding question on the statistical basis of the bracket

Abstract

We consider the Vlasov equation in any spatial dimension, which has long been known to be an infinite-dimensional Hamiltonian system whose bracket structure is of Lie-Poisson type. In parallel, it is classical that the Vlasov equation is a mean-field limit for a pairwise interacting Newtonian system. Motivated by this knowledge, we provide a rigorous derivation of the Hamiltonian structure of the Vlasov equation, both the Hamiltonian functional and Poisson bracket, directly from the many-body problem. One may view this work as a classical counterpart to arXiv:1908.03847, which provided a rigorous derivation of the Hamiltonian structure of the cubic nonlinear Schr\"odinger equation from the many-body problem for interacting bosons in a certain infinite particle number limit, the first result of its kind. In particular, our work settles a question of Marsden, Morrison, and Weinstein on providing a "statistical basis" for the bracket structure of the Vlasov equation.