Singular and non-singular endstates in massless scalar field collapse

TL;DR

This paper investigates the gravitational collapse of a massless scalar field, identifying conditions for black hole formation and discovering solutions where collapse halts, preventing singularities and black hole formation.

Contribution

It introduces new classes of solutions showing both black hole formation and non-singular endstates in massless scalar field collapse.

Findings

Identified black hole solutions in scalar field collapse

Discovered solutions where collapse halts without forming a black hole

Found non-singular endstates with frozen scalar fields

Abstract

We study the collapse of a massless scalar field coupled to gravity. A class of blackhole solutions are identified. We also report on a class of solutions where collapse starts from a regular spacelike surface but then the collapsing scalar field freezes. As a result, in these solutions, a black hole does not form, neither is there any singularity in the future.