Well-posedness and long-time behavior for self-consistent Vlasov-Fokker-Planck equations with general potentials

Abstract: We study the well-posedness, steady states and long time behavior of solutions to Vlasov-Fokker-Planck equation with external confinement potential and nonlinear self-consistent interactions. Our analysis introduces newly characterized conditions on the interaction kernel that ensure the local asymptotic stability of the unique steady state. Compared to previous works on this topic, our results allow for large, singular and non-symmetric interactions. As a corollary of our main results, we show exponential decay of solutions to the Vlasov-Poisson-Fokker-Planck equation in dimension $3$, for low regularity initial data. In the repulsive case, the result holds in strongly nonlinear regimes (\emph{i.e.} for arbitrarily small Debye length). Our techniques rely on the design of new Lyapunov functionals based on hypocoercivity and hypoellipticity theories. We use norms which include part of the interaction kernel, and carefully mix macroscopic quantities based''--hypocoercivity withcommutators based''--hypocoercivity.