Ambient cosmology and spacetime singularities

TL;DR

This paper introduces a novel approach linking 4D spacetime singularities to the asymptotic properties of a 5D ambient metric, offering new insights into cosmic censorship and singularity constraints.

Contribution

It proposes a new framework connecting 4D singularities with 5D ambient metrics, advancing understanding of cosmic censorship in general relativity.

Findings

Spacetime singularities are constrained by the asymptotic properties of the ambient 5-metric.

Non-degeneracy of the ambient metric depends on cosmic censorship holding on the boundary.

The approach offers a new perspective on the relationship between singularities and higher-dimensional geometry.

Abstract

We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary.