Gravitational collapse in 2+1 dimensional AdS spacetime

TL;DR

This paper reports numerical simulations of black hole formation from scalar field collapse in 2+1 dimensional AdS spacetime, revealing a universal critical solution with self-similarity and a specific mass-scaling exponent.

Contribution

It introduces a novel numerical approach with singularity excision to study interior structures and critical phenomena in 2+1D AdS gravitational collapse.

Findings

Exterior geometry approaches BTZ black hole solution

A strong, spacelike curvature singularity forms inside the horizon

Critical behavior exhibits self-similarity with a mass-scaling exponent of ~1.2

Abstract

We present results of numerical simulations of the formation of black holes from the gravitational collapse of a massless, minimally-coupled scalar field in 2+1 dimensional, axially-symmetric, anti de-Sitter (AdS) spacetime. The geometry exterior to the event horizon approaches the BTZ solution, showing no evidence of scalar `hair'. To study the interior structure we implement a variant of black-hole excision, which we call singularity excision. We find that interior to the event horizon a strong, spacelike curvature singularity develops. We study the critical behavior at the threshold of black hole formation, and find a continuously self-similar solution and corresponding mass-scaling exponent of approximately 1.2. The critical solution is universal to within a phase that is related to the angle deficit of the spacetime.