Semi-classical geometry of charged black holes

TL;DR

This paper explores how quantum effects modify the classical geometry of two-dimensional charged black holes, showing that pair-creation destabilizes the inner horizon and results in a spacelike singularity, altering the black hole's internal structure.

Contribution

It provides a systematic study of quantum back-reaction on charged black holes in two dimensions, revealing the destabilization of the inner horizon due to pair-creation effects.

Findings

Quantum effects replace the inner horizon with a spacelike singularity.

Back-reaction due to pair-creation destabilizes classical inner horizons.

Semi-classical geometry retains the same global topology as neutral black holes.

Abstract

At the classical level, two-dimensional dilaton gravity coupled to an abelian gauge field has charged black hole solutions, which have much in common with four-dimensional Reissner-Nordstrom black holes, including multiple asymptotic regions, timelike curvature singularities, and Cauchy horizons. The black hole spacetime is, however, significantly modified by quantum effects, which can be systematically studied in this two-dimensional context. In particular, the back-reaction on the geometry due to pair-creation of charged fermions destabilizes the inner horizon and replaces it with a spacelike curvature singularity. The semi-classical geometry has the same global topology as an electrically neutral black hole.