The large-scale structure of the ambient boundary

TL;DR

This paper reviews the ambient cosmological metric, exploring its implications for the universe's global geometry, including boundary topology, singularity absence, and cosmic censorship, within a novel 5-geometry framework satisfying Einstein equations.

Contribution

It introduces a new ambient metric construction that links the universe's boundary to a higher-dimensional geometry satisfying Einstein equations, with implications for cosmic censorship.

Findings

Boundary of the ambient metric has a specific topological structure.

Spacetime singularities are absent on the boundary.

Cosmic censorship follows from a new boundary principle.

Abstract

This article gives a review of a recent construction, the ambient cosmological metric, and its implications for the global geometry of the universe. According to this proposal, the universe is a bounding hypersurface carrying a conformal structure and lying at the (conformal) infinity of a new, 5-geometry which satisfies the Einstein equations with fluid sources. We discuss our main results about the implied topological nature of the conformal infinity of the ambient metric, the non-existence of spacetime singularities on the boundary, as well as the validity of cosmic censorship as a direct consequence of a new principle on the boundary.