Thermodynamics with Pressure and Volume under Charged Particle Absorption

TL;DR

This paper examines how charged anti-de Sitter black holes behave under charged particle absorption when considering thermodynamic volume, revealing a second law violation in certain cases but preserving the weak cosmic censorship conjecture.

Contribution

It introduces the analysis of thermodynamic volume in black hole absorption processes, highlighting second law violations for extremal cases while confirming the weak cosmic censorship conjecture.

Findings

Decreased entropy for extremal and near-extremal black holes under absorption.

Second law violation occurs only when thermodynamic volume is considered.

Weak cosmic censorship conjecture remains valid despite entropy violations.

Abstract

We investigate the variation of the charged anti-de Sitter black hole under charged particle absorption by considering thermodynamic volume. The variation exactly corresponds to that expected as the first law of thermodynamics. Nevertheless, we find the decrease of the Bekenstein-Hawking entropy for extremal and near-extremal black holes under the absorption to be an irreversible process. This violation of the second law of thermodynamics is only found in the case considering thermodynamic volume. We test the weak cosmic censorship conjecture affected by the violation. Fortunately, the conjecture is still valid. However, extremal and near-extremal black holes do not change their configurations under the absorption. This is quite different from the case without thermodynamic volume.