Black Hole Chemistry

TL;DR

This paper introduces a novel perspective on black hole thermodynamics by equating black hole mass with chemical enthalpy and the cosmological constant with pressure, revealing complex phase behaviors similar to chemical systems.

Contribution

It proposes a new thermodynamic framework for black holes, linking gravitational physics with chemical thermodynamics concepts like Van der Waals fluids and phase transitions.

Findings

Black holes exhibit Van der Waals-like phase behavior.

Charged and rotating black holes show reentrant phase transitions.

Identification of the cosmological constant as thermodynamic pressure.

Abstract

The mass of a black hole has traditionally been identified with its energy. We describe a new perspective on black hole thermodynamics, one that identifies the mass of a black hole with chemical enthalpy, and the cosmological constant as thermodynamic pressure. This leads to an understanding of black holes from the viewpoint of chemistry, in terms of concepts such as Van der Waals fluids, reentrant phase transitions, and triple points. Both charged and rotating black holes exhibit novel chemical-type phase behaviour, hitherto unseen.