Formation and Evaporation of Charged Black Holes

TL;DR

This paper models the formation and evaporation of charged black holes, including Hawking radiation and discharge processes, providing insights into their evolution and lifetime within a semiclassical framework.

Contribution

It presents a self-consistent semiclassical analysis of charged black hole dynamics, incorporating both mass evaporation and charge discharge mechanisms.

Findings

Black holes tend toward extremality during evaporation.

Discharge and evaporation can occur simultaneously, leading to regular decay.

Estimated black hole lifetimes depend on charge and mass loss rates.

Abstract

We investigate the dynamical formation and evaporation of a spherically symmetric charged black hole. We study the self-consistent one loop order semiclassical back-reaction problem. To this end the mass-evaporation is modeled by an expectation value of the stress-energy tensor of a neutral massless scalar field, while the charge is not radiated away. We observe the formation of an initially non extremal black hole which tends toward the extremal black hole $M=Q$, emitting Hawking radiation. If also the discharge due to the instability of vacuum to pair creation in strong electric fields occurs, then the black hole discharges and evaporates simultaneously and decays regularly until the scale where the semiclassical approximation breaks down. We calculate the rates of the mass and the charge loss and estimate the life-time of the decaying black holes.