Singularity avoidance in quantum gravity

TL;DR

This paper explores how quantum gravity effects, including higher-derivative terms and quantum corrections, can potentially resolve classical singularities in spacetime by analyzing geodesic behavior and extending singularity theorems.

Contribution

It demonstrates that quantum gravity modifications can eliminate singularities and generalizes classical theorems to include quantum one-loop effects.

Findings

Higher-derivative terms can prevent singularity formation.

Quantum corrections modify classical geodesic convergence.

Singularities are not inevitable in quantum gravity models.

Abstract

The purpose of this work is to investigate the consequences of quantum gravity for the singularity problem. We study the higher-derivative terms that invariably appear in any quantum field theoretical model of gravity, handling them both non-perturbatively and perturbatively. In the former case, by computing the contributions of the additional degrees of freedom to a congruence of geodesics, we show that the appearance of singularities is no longer a necessity. In the latter, which corresponds to treating the quantised general relativity as an effective field theory, we generalise the Hawking-Penrose theorems to include one-loop corrections of both massless matter and graviton fluctuations.