On the Dynamics of Near-Extremal Black Holes

TL;DR

This paper investigates the dynamics of near-extremal Reissner-Nordstr"om black holes in AdS$_4$, showing their behavior aligns with the JT gravity model and highlighting the universal role of symmetry breaking in such systems.

Contribution

It demonstrates that the low-energy dynamics of near-extremal black holes can be effectively described by the JT model, emphasizing the universality of symmetry-breaking effects.

Findings

Behavior matches the JT gravity model at low energies.

Symmetry considerations explain the dynamics.

Features are universal in near-extremal black holes.

Abstract

We analyse the dynamics of near-extremal Reissner-Nordstr\"om black holes in asymptotically four-dimensional Anti-de Sitter space (AdS$_4$). We work in the spherically symmetric approximation and study the thermodynamics and the response to a probe scalar field. We find that the behaviour of the system, at low energies and to leading order in our approximations, is well described by the Jackiw-Teitelboim (JT) model of gravity. In fact, this behaviour can be understood from symmetry considerations and arises due to the breaking of time reparametrisation invariance. The JT model has been analysed in considerable detail recently and related to the behaviour of the SYK model. Our results indicate that features in these models which arise from symmetry considerations alone are more general and present quite universally in near-extremal black holes.