Interior design of a two-dimensional semiclassical black hole: Quantum transition across the singularity

TL;DR

This paper investigates the internal quantum structure of a two-dimensional evaporating black hole, showing that quantum effects can resolve the classical singularity and allow spacetime to extend beyond it.

Contribution

It introduces a simplified quantum model near the black hole singularity, demonstrating regular quantum evolution and potential extension of spacetime beyond the classical singularity.

Findings

Quantum evolution remains regular at the singularity.

Wave-packets bounce off the singularity while maintaining localization.

Spacetime may extend beyond the classical singularity semiclassically.

Abstract

We study the internal structure of a two-dimensional dilatonic evaporating black hole, based on the CGHS model. At the semiclassical level, a (weak) spacelike singularity was previously found to develop inside the black hole. We employ here a simplified quantum formulation of spacetime dynamics in the neighborhood of this singularity, using a minisuperspace-like approach. Quantum evolution is found to be regular and well-defined at the semiclassical singularity. A well-localized initial wave-packet propagating towards the singularity bounces off the latter and retains its well-localized form. Our simplified quantum treatment thus suggests that spacetime may extend semiclassically beyond the singularity, and also signifies the specific extension.