Comparison of thermodynamic behaviors of two regular-AdS black holes

Abstract

Considering the negative cosmological constant of an anti-de Sitter (AdS) background as a positive thermodynamic pressure in the extended phase space, we investigate the P−υ critical behavior and of the cooling–heating phase transition of the regular Hayward-AdS (HAdS) black hole (BH), and compare the difference of some thermodynamic processes in both the HAdS BH and the Bardeen-AdS (BAdS) BH. We 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 obtained 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 for these two BHs. The results suggested that the inner horizon and the outer horizon of the Hayward BH are easier to merge, and the singularity is easier to expose.