Semiclassical dynamics of horizons in spherically symmetric collapse

TL;DR

This paper explores how loop quantum gravity corrections modify the classical gravitational collapse of a scalar field, replacing singularities with bounces and analyzing horizon formation during the semiclassical evolution.

Contribution

It introduces a semiclassical model with holonomy corrections for spherically symmetric collapse, demonstrating singularity resolution and deriving conditions for horizon formation.

Findings

Singularity replaced by a bounce due to quantum effects

Threshold radius for horizon formation identified

Quantum corrections influence the exterior boundary conditions

Abstract

In this work, we consider a semiclassical description of the spherically symmetric gravitational collapse with a massless scalar field. In particular, we employ an effective scenario provided by holonomy corrections from loop quantum gravity, to the homogeneous interior spacetime. The singularity that would arise at the final stage of the corresponding classical collapse, is resolved in this context and is replaced by a bounce. Our main purpose is to investigate the evolution of trapped surfaces during this semiclassical collapse. Within this setting, we obtain a threshold radius for the collapsing shells in order to have horizons formation. In addition, we study the final state of the collapse by employing a suitable matching at the boundary shell from which quantum gravity effects are carried to the exterior geometry.