Suppression of spacetime singularities in quantum gravity

TL;DR

This paper explores how quantum gravity can suppress spacetime singularities through destructive interference in the path integral, revealing that such suppression requires the gravitational action to be of infinite order in curvature.

Contribution

It introduces a novel constraint on the microscopic gravitational action, showing that singularity suppression necessitates an infinite-order curvature action in the path integral.

Findings

Complete singularity suppression implies an infinite-order curvature action.

Simple static spherically symmetric examples illustrate the suppression mechanism.

The approach links singularity resolution to the form of the gravitational action.

Abstract

We investigate the requirement of suppressing spacetime geometries with a curvature singularity via destructive interference in the Lorentzian gravitational path integral as a constraint on the microscopic action for gravity. Based on simple examples of static spherically symmetric spacetimes, we demonstrate that complete singularity suppression in the path integral stipulates that the action for gravity be of infinite order in the curvature.