Evaporation of a two-dimensional charged black hole

TL;DR

This paper models a two-dimensional charged black hole, analyzing its evaporation process and how the charge-to-mass ratio evolves under different electromagnetic coupling regimes.

Contribution

It introduces a dilatonic 2D charged black hole model and explores its semiclassical evaporation dynamics, revealing two distinct regimes based on the coupling constant.

Findings

Charge-to-mass ratio decays to zero for strong coupling.

Charge-to-mass ratio approaches a non-zero constant for weak coupling.

Evaporation rate depends on initial parameters and coupling constant.

Abstract

We construct a dilatonic two-dimensional model of a charged black hole. The classical solution is a static charged black hole, characterized by two parameters, $m$ and $q$, representing the black hole's mass and charge. Then we study the semiclassical effects, and calculate the evaporation rate of both $m$ and $q$, as a function of these two quantities. Analyzing this dynamical system, we find two qualitatively different regimes, depending on the electromagnetic coupling constant $g_{A}$. If the latter is greater than a certain critical value, the charge-to-mass ratio decays to zero upon evaporation. On the other hand, for $g_{A}$ smaller than the critical value, the charge-to-mass ratio approaches a non-zero constant that depends on $g_{A}$ but not on the initial values of $m$ and $q$.