Statistical Mechanics of Unbound Two Dimensional Self-Gravitating Systems

Abstract

We study, using both theory and molecular dynamics simulations, the relaxation dynamics of a microcanonical two dimensional self-gravitating system. After a sufficiently large time, a gravitational cluster of N particles relaxes to the Maxwell-Boltzmann distribution. The time to reach the thermodynamic equilibrium, however, scales with the number of particles. In the thermodynamic limit, $N\to \infty$ at fixed total mass, equilibrium state is never reached and the system becomes trapped in a non-ergodic stationary state. An analytical theory is presented which allows us to quantitatively described this final stationary state, without any adjustable parameters.

References in corpus (5)

• Statistical mechanics and dynamics of solvable models with long-range interactions
• Collisionless relaxation in non-neutral plasmas
• Collisionless relaxation in gravitational systems: From violent relaxation to gravothermal collapse
• Violation of the Zeroth Law of Thermodynamics in Systems with Negative Specific Heat
• Relaxation times of unstable states in systems with long range interactions

Cited by in corpus (3)

• Core-halo distribution in the Hamiltonian Mean-Field Model
• Statistical mechanics of collisionless relaxation in a noninteracting system
• Topology of Collisionless Relaxation