Exact black hole formation in three dimensions

TL;DR

This paper presents exact solutions describing black hole formation through gravitational collapse in three-dimensional Einstein gravity coupled to a scalar field, highlighting the asymptotic AdS nature and geometric properties.

Contribution

It provides the first exact time-dependent solutions for scalar field-induced black hole formation in three dimensions, including both non-minimal and minimal coupling cases.

Findings

Exact time-dependent spherically symmetric solutions obtained

Black hole formation occurs at infinite time in the static limit

Solutions are asymptotically AdS due to a No-Go theorem

Abstract

We consider three dimensional Einstein gravity non-minimally coupled to a real scalar field with a self-interacting scalar potential and present the exact black hole formation in three dimensions. Firstly we obtain an exact time-dependent spherically symmetric solution describing the gravitational collapse to a scalar black hole at the infinite time, i.e. in the static limit. The solution can only be asymptotically AdS because of the No-Go theorem in three dimensions which is resulted from the existence of a smooth black hole horizon. Then we analyze their geometric properties and properties of the time evolution. We also get the exact time-dependent solution in the minimal coupling model after taking a conformal transformation.