Different thermodynamics of self-gravitating systems and discussions for some observations and simulations

TL;DR

This paper explores the thermodynamics of self-gravitating systems, proposing a statistical mechanics framework based on ergodicity breaking and Boltzmann entropy, and compares it with observations and simulations.

Contribution

It introduces a novel thermodynamic approach for self-gravitating systems using ergodicity breaking and Boltzmann entropy, providing new insights into their density profiles and phenomena like gravothermal catastrophe.

Findings

Thermodynamics of self-gravitating systems can be described with ergodicity breaking.

The gravothermal catastrophe is a special case within this new framework.

Non-universal density profiles are not due to initial collapse factors.

Abstract

Our previous works have shown the statistical mechanics of self-gravitating system. In this paper, we will show its thermodynamics and compare our results with observations and simulations. We propose that our statistical mechanics can be based on ergodicity breaking and Boltzmann entropy, and its assumptions do not contradict with the reality. With the principle of statistical mechanics, we will show our definition of temperature and then the capacity of self-gravitating systems. We find that the gravothermal catastrophe may be a special case of our theory. Our results also provide new explanations for the density profiles of observations and numerical simulations, especially we think that the non-universal density distribution in the simulations of dissipationless collapse is not caused by the different initial collapse factor. We will also discuss about the core-cusp problem.