Spherical collapse and black hole evaporation

TL;DR

This paper models spherically symmetric black hole formation and evaporation using classical and semiclassical gravity, revealing a potential quantum extension of null infinity where information may be recovered.

Contribution

It introduces a semiclassical framework for black hole evaporation with a specific scalar coupling, and suggests a quantum extension of null infinity for information retrieval.

Findings

Classical collapse described by Vaidya solution

Semiclassical Einstein equations are well-defined

A quantum extension of null infinity is proposed

Abstract

We consider spherically symmetric gravity coupled to a spherically symmetric scalar field with a specific coupling which depends on the Areal Radius. Classical collapse is described by the Vaidya solution. The semiclassical Einstein equations are well defined. Their solution describes an evaporating black hole. A balance law at future null infinity relates the rate of change of a back reaction-corrected Bondi mass to a manifestly positive flux. Its detailed form suggests a quantum extension of future null infinity along which all information including that in the collapsing matter is expected to emerge.