Non-perturbative quantum gravity denounces singular Black Holes

TL;DR

This paper demonstrates that in a non-perturbative, ghost-free infinite derivative gravity framework, classical black hole singularities are avoided unless considering an unphysical infinite mass scenario, challenging traditional singularity predictions.

Contribution

It shows that the form of the graviton propagator in non-perturbative gravity models determines the absence of black hole singularities, providing a potential resolution to classical singularities.

Findings

Singular solutions are absent for physically realistic graviton propagators.

A non-singular black hole interior is consistent with unitarity and ghost-free conditions.

Singularities only arise in unphysical infinite mass cases.

Abstract

Although General Relativity predicts the presence of a singularity inside of a Black Hole, it is not a complete theory of gravity. A real structure of a Black Hole interior near an expected singularity depends on the UV completion of gravity. In this paper, we establish that the question whether singular spherically symmetric solutions are absent is governed by the functional form of a non-perturbative graviton propagator. We explicitly show in a framework of a ghost-free infinite derivative gravity that for the graviton propagator of an exponential form favored by the unitarity a singularity is not possible unless an unphysical situation when the total mass of the Black Hole is infinite is considered.