A black hole mass threshold from non-singular quantum gravitational collapse

TL;DR

This paper demonstrates that non-perturbative effects of Loop Quantum Gravity can cause a bounce in collapsing scalar fields, removing singularities and establishing a threshold below which black holes do not form.

Contribution

It introduces a toy model showing quantum gravity effects prevent singularities and set a minimum size for black hole formation.

Findings

Quantum gravity causes a bounce in collapse models.

No horizon forms below a certain critical scale.

Singularities are resolved by quantum effects.

Abstract

Quantum gravity is expected to remove the classical singularity that arises as the end-state of gravitational collapse. To investigate this, we work with a toy model of a collapsing homogeneous scalar field. We show that non-perturbative semi-classical effects of Loop Quantum Gravity cause a bounce and remove the black hole singularity. Furthermore, we find a critical threshold scale, below which no horizon forms -- quantum gravity may exclude very small astrophysical black holes.