Joule-Thomson expansion in AdS black holes with momentum relaxation

TL;DR

This paper explores the Joule-Thomson effect in AdS black holes with broken translational symmetry, revealing complex inversion curves and novel heating behavior during phase transitions.

Contribution

It introduces holographic models of momentum relaxation in black holes and analyzes their Joule-Thomson expansion, showing new inversion curve structures and heating phenomena.

Findings

Inversion curves with two branches similar to Van der Waals fluids.

Black holes can heat up when crossing the inversion curve in massive gravity models.

Momentum relaxation affects the thermodynamic behavior of AdS black holes.

Abstract

The inner structure of realistic materials make them exhibit momentum relaxation. In this paper we study the holographic version of the Joule-Thomson effect on AdS black holes in which translational invariance is broken by two methods: First by considering planar black holes in general relativity supported by axion scalar fields with a linear dependence on the horizon coordinates and secondly by considering black holes in massive gravity models in which momentum relaxation is obtained by breaking the bulk diffeomorphism invariance of the theory. In contrast with black holes studied so far, for both theories it is possible to obtain inversion curves with two branches reproducing the behavior of Van der Wall fluids. Moreover in the specific case of the massive gravity model we show that black holes can heat up when crossing the inversion curve.