Charge Loss (or the Lack Thereof) for AdS Black Holes

TL;DR

This paper investigates the charge loss behavior of AdS Reissner-Nordstrom black holes, revealing that unlike asymptotically flat black holes, they tend to become extremal due to inefficient charge loss, with implications for black hole evolution.

Contribution

The study extends charge loss modeling to AdS black holes and explains why they evolve towards extremality, contrasting with flat spacetime black holes.

Findings

AdS black holes tend to become extremal during evaporation.

Charge loss in AdS black holes is inefficient compared to flat spacetime.

The underlying reason for different charge evolution behaviors is clarified.

Abstract

The evolution of evaporating charged black holes is complicated to model in general, but is nevertheless important since the hints to the Information Loss Paradox and its recent firewall incarnation may lie in understanding more generic geometries than that of Schwarzschild spacetime. Fortunately, for sufficiently large asymptotically flat Reissner-Nordstrom black holes, the evaporation process can be modeled via a system of coupled linear ordinary differential equations, with charge loss rate governed by Schwinger pair-production process. The same model can be generalized to study the evaporation of AdS Reissner-Nordstrom black holes with flat horizon. It was recently found that such black holes always evolve towards extremality since charge loss is inefficient. This property is completely opposite to the asymptotically flat case in which the black hole eventually loses its charges and tends towards Schwarzschild limit. We clarify the underlying reason for this different behavior.