Scalar field black holes

TL;DR

This paper studies the gravitational collapse of a scalar field into a black hole, revealing that the black hole's mass inversely relates to the scalar field's mass, with implications for axion-like particles.

Contribution

It introduces a decomposition of the scalar field's energy-momentum tensor to analyze collapse, showing the formation of scalar field black holes with specific mass relations.

Findings

Scalar field collapse results in black holes with mass inversely proportional to scalar mass.

The black hole mass for axion-like particles is approximately 10^-5 solar masses.

Collapse leads to a singularity under the studied conditions.

Abstract

With a suitable decomposition of its energy-momentum tensor into pressureless matter and a vacuum type term, we investigate the spherical gravitational collapse of a minimally coupled, self-interacting scalar field, showing that it collapses to a singularity. The formed blackhole has a mass $M \sim 1/m$ (in Planck units), where $m$ is the mass of the scalar field. If the latter has the axion mass, $m \sim 10^{-5}$ eV, the former has a mass $M \sim 10^{-5} M_{\odot}$.