Comparison of thermodynamic behaviors of two regular-AdS black holes

TL;DR

This paper compares the thermodynamic behaviors of Hayward-AdS and Bardeen-AdS black holes, analyzing phase transitions and horizon properties, revealing differences in phase transition types and horizon merging tendencies.

Contribution

It provides a comparative analysis of thermodynamic phase transitions and horizon behaviors between two regular AdS black holes, highlighting their distinct properties.

Findings

BAdS black holes tend to exhibit van der Waals-like phase transitions.

HAdS black holes have higher inversion curves under the same conditions.

Hayward black holes' horizons merge more easily, exposing singularities.

Abstract

Considering the negative cosmological constant of an anti-de Sitter (AdS) background as a positive thermodynamic pressure in the extended phase space, we study the thermodynamic behaviors of the regular Hayward-AdS (HAdS) black hole (BH) by investigating $P-\upsilon$ critical and cooling-heating phase transition. We compare the difference of two thermodynamic processes between the HAdS BH and the Bardeen-AdS (BAdS) BH. It is found that the phase transition of the BAdS BH tends to be more the van der Waals (vdW) phase transition. For the cooling-heating phase transition, we find the inversion curves of the HAdS BH are always higher than the BAdS BH under the same pressure and magnetic charge. We also compare the smallest existence mass, the zero-temperature remnant, and the critical magnetic charge. The results suggest that the inner horizon and the outer horizon of the Hayward BH are easier to merge, and the singularity is easier to expose.