Definition and classification of singularities in GR: classical and quantum

TL;DR

This paper reviews the classification of classical and quantum singularities in general relativity, highlighting how quantum effects can resolve classical singularities, with examples and new results on quasiregular spacetimes.

Contribution

It provides a comprehensive review of singularity classifications and introduces findings on how quantum effects can eliminate classical singularities in certain spacetimes.

Findings

Quantum singularities can differ from classical ones in specific spacetimes.

A strong repulsive potential near classical singularities can prevent quantum singularities.

Examples of spacetimes where quantum effects resolve classical singularities.

Abstract

We will briefly review the definition and classification of classical and quantum singularities in general relativity. Examples of classically singular spacetimes that do not have quantum singularities will be given. We will present results on quantum singularities in quasiregular spacetimes. We will also show that a strong repulsive "potential" near the classical singularity can turn a classically singular spacetime into a quantum mechanically nonsingular spacetime.