Collapse and evaporation of a canonical self-gravitating gas

TL;DR

This paper explores the out-of-equilibrium behaviors of a self-gravitating gas under friction and random forces, analyzing conditions leading to equilibrium, collapse, or evaporation across different dimensions and parameters.

Contribution

It provides a comprehensive dynamical phase diagram for a canonical self-gravitating gas with a specific density-dependent diffusion coefficient.

Findings

System can reach equilibrium, collapse, or evaporate depending on parameters.

Phase diagram maps out different dynamical regimes.

Results depend on dimension, temperature, and confinement.

Abstract

We review the out-of-equilibrium properties of a self-gravitating gas of particles in the presence of a strong friction and a random force (canonical gas). We assume a bare diffusion coefficient of the form $D(\rho)=T\rho^{1/n}$, where $\rho$ is the local particle density, so that the equation of state is $P(\rho)=D(\rho)\rho$. Depending on the spatial dimension $d$, the index $n$, the temperature $T$, and whether the system is confined to a finite box or not, the system can reach an equilibrium state, collapse or evaporate. This article focuses on the latter cases, presenting a complete dynamical phase diagram of the system.