Thermal analysis and Joule-Thomson expansion of black hole exhibiting metric-affine gravity

TL;DR

This paper investigates the thermodynamics, phase transitions, and Joule-Thomson expansion of a black hole solution in metric-affine gravity, highlighting stability conditions and heat engine efficiency.

Contribution

It introduces a detailed thermodynamic analysis of a metric-affine gravity black hole, including phase transitions, stability, and comparison with Van der Waals fluids.

Findings

Phase transition from unstable to stable states with first law corrections.

Joule-Thomson inversion temperature and isenthalpic curves analyzed.

Black hole thermodynamics shows similarities to Van der Waals fluid.

Abstract

This study examines a recently hypothesized black hole, which is a perfect solution of metric-affine gravity with a positive cosmological constant, and its thermodynamic features as well as the Joule-Thomson expansion. We develop some thermodynamical quantities, such as volume, Gibbs free energy, and heat capacity, using the entropy and Hawking temperature. We also examine the first law of thermodynamics and thermal fluctuations, which might eliminate certain black hole instabilities. In this regard, a phase transition from unstable to stable is conceivable when the first law order corrections are present. Besides that, we study the efficiency of this system as a heat engine and the effect of metric-affine gravity for physical parameters $q_e$, $q_m$, $\kappa_{\mathrm{s}}$, $\kappa_{\mathrm{d}}$ and $\kappa_{\mathrm{sh}}$. Further, we study the Joule-Thomson coefficient, and the inversion temperature and also observed the isenthalpic curves in the $T_i -P_i$ plane. In metric-affine gravity, a comparison is made between the Van der Waals fluid and the black hole to study their similarities and differences.