A Hamiltonian approach for the Thermodynamics of AdS black holes

TL;DR

This paper introduces a Hamiltonian framework for the thermodynamics of D-dimensional Schwarzschild-AdS black holes, incorporating the cosmological constant as a thermodynamic variable and deriving a comprehensive equation of state.

Contribution

It extends minimal black hole thermodynamics by using a Hamiltonian approach with an additional degree of freedom, enabling a consistent description including the cosmological constant.

Findings

Introduces a Hamiltonian method for SAdS thermodynamics.

Derives a new equation of state for SAdS black holes.

Links thermodynamic constants to boundary conditions in microscopic theories.

Abstract

In this work we study the Thermodynamics of D-dimensional Schwarzschild-anti de Sitter (SAdS) black holes. The minimal Thermodynamics of the SAdS spacetime is briefly discussed, highlighting some of its strong points and shortcomings. The minimal SAdS Thermodynamics is extended within a Hamiltonian approach, by means of the introduction of an additional degree of freedom. We demonstrate that the cosmological constant can be introduced in the thermodynamic description of the SAdS black hole with a canonical transformation of the Schwarzschild problem, closely related to the introduction of an anti-de Sitter thermodynamic volume. The treatment presented is consistent, in the sense that it is compatible with the introduction of new thermodynamic potentials, and respects the laws of black hole Thermodynamics. By demanding homogeneity of the thermodynamic variables, we are able to construct a new equation of state that completely characterizes the Thermodynamics of SAdS black holes. The treatment naturally generates phenomenological constants that can be associated with different boundary conditions in underlying microscopic theories. A whole new set of phenomena can be expected from the proposed generalization of SAdS Thermodynamics.