Gravothermal Catastrophe with a Cosmological Constant

TL;DR

This paper explores how a cosmological constant influences the gravothermal catastrophe, revealing that negative values destabilize while positive values stabilize the system, leading to new critical phenomena.

Contribution

It introduces the concept of a reentrant behavior and identifies a second critical radius, expanding understanding of thermodynamic stability in gravitational systems with a cosmological constant.

Findings

Negative cosmological constant destabilizes the system

Positive cosmological constant stabilizes the system

Discovery of a second critical radius and inverse Antonov transition

Abstract

We investigate the effect of a cosmological constant on the gravothermal catastrophe in the Newtonian limit. A negative cosmological constant acts as a thermodynamic `destabilizer'. The Antonov radius gets smaller and the instability occurs, not only for negative but also for positive energy values. A positive cosmological constant acts as a `stabilizer' of the system, which, in this case, exhibits a novel `reentrant behaviour'. In addition to the Antonov radius we find a second critical radius, where an `inverse Antonov transition' occurs; a series of local entropy maxima is restored.