Black Hole Evaporation by Thermal Bath Removal

TL;DR

This paper investigates the semiclassical evaporation of 2D black holes in thermal equilibrium when radiation input ceases, revealing that the end-state geometry matches that of black holes formed by collapse, with some models showing non-complete evaporation.

Contribution

It introduces a family of exactly solvable 2D dilaton gravity models analyzing black hole evaporation and end-states, including models with temperature proportional to mass.

Findings

End-state geometry matches evaporating collapse black holes

Black holes in certain models do not fully evaporate

Exact semiclassical solutions describe quantum evolution

Abstract

We study the evaporation process of 2D black holes in thermal equilibrium when the incoming radiation is turned off. Our analysis is based on two different classes of 2D dilaton gravity models which are exactly solvable in the semiclassical aproximation including back-reaction. We consider a one parameter family of models interpolating between the Russo-Susskind-Thorlacius and Bose-Parker-Peleg models. We find that the end-state geometry is the same as the one coming from an evaporating black hole formed by gravitational collapse. We also study the quantum evolution of black holes arising in a model with classical action $S = {1\over2\pi} \int d^2x \sqrt{-g} (R\phi + 4\lambda^2e^{\beta\phi})$. The black hole temperature is proportional to the mass and the exact semiclassical solution indicates that these black holes never disappear completely.