Nonequilibrium Stationary States of 3D Self-Gravitating Systems

Abstract

Three-dimensional self-gravitating systems do not evolve to thermodynamic equilibrium but become trapped in nonequilibrium quasistationary states. In this Letter, we present a theory which allows us to a priori predict the particle distribution in a final quasistationary state to which a self-gravitating system will evolve from an initial condition which is isotropic in particle velocities and satisfies a virial constraint $2K=\ensuremath{-}U$, where $K$ is the total kinetic energy, and $U$ is the potential energy of the system.