Critical behavior of charged Gauss-Bonnet AdS black holes in the grand canonical ensemble

TL;DR

This paper investigates the thermodynamic phase transitions of charged Gauss-Bonnet-AdS black holes in various dimensions and topologies within the grand canonical ensemble, revealing conditions for Van der Waals-like behavior and its absence.

Contribution

It identifies the specific conditions under which small-large black hole phase transitions occur in charged Gauss-Bonnet-AdS black holes, extending understanding beyond Reissner-Nordstrom-AdS cases.

Findings

Van der Waals-like phase transition occurs in 5D spherical charged Gauss-Bonnet-AdS black holes with potential in 0<Φ<√3π/4.

No such phase transition in higher dimensions or topologies.

Reissner-Nordstrom-AdS black holes show no critical behavior in the grand canonical ensemble.

Abstract

We study the thermodynamics in the grand canonical ensemble of D-dimensional charged Gauss-Bonnet-AdS black holes in the extended phase space. We find that the usual small-large black hole phase transition, which exhibits analogy with the Van de Waals liquid-gas system holds in five-dimensional spherical charged Gauss-Bonnet-AdS black holes when its potential is fixed within the range $0<\Phi<\frac{\sqrt{3}\pi}{4}$. For the other higher dimensional and topological charged Gauss-Bonnet-AdS black holes, there is no such phase transition. In the limiting case, Reissner-Nordstrom-AdS black holes, with vanishing Gauss-Bonnet parameter, there is no critical behavior in the grand canonical ensemble. This result holds independent of the spacetime dimensions and topologies. We also examine the behavior of physical quantities in the vicinity of the critical point in the five-dimensional spherical charged Gauss-Bonnet-AdS black holes.