Singularity theorems in the effective field theory for quantum gravity at second order in curvature

TL;DR

This paper investigates how effective field theory in quantum gravity, including new massive fields at second order in curvature, can lead to violations of classical singularity theorems in cosmology and black hole physics.

Contribution

It demonstrates that the inclusion of a massive spin-2 and a scalar field at second order in curvature can invalidate key singularity theorems, revealing potential quantum gravity effects.

Findings

Massive spin-2 field can invalidate cosmological and black hole singularity theorems.

Massive scalar field can violate assumptions of Hawking's theorem.

Penrose's singularity theorem remains unaffected by these fields.

Abstract

In this paper we discuss singularity theorems in quantum gravity using effective field theory methods. To second order in curvature, this effective field theory contains two new degrees of freedom which have important implications for the derivation of these energy theorems: a massive spin-2 field and a massive spin-0 field. Using an explicit mapping of this theory from the Jordan frame to the Einstein frame, we show that both the cosmological and the black hole singularity theorems may not hold due to the presence of a massive spin-2 field in the particle spectrum of quantum gravity. Furthermore, we show that the massive scalar field can lead to a violation of the assumptions used to derive Hawking's singularity theorem. On the other hand, it does not affect Penrose's singularity theorem.