Novel rotating hairy black hole in (2+1)-dimensions

TL;DR

This paper introduces a new exact rotating hairy black hole solution in (2+1)-dimensional Einstein-scalar-AdS theory, revealing how scalar potential parameters relate to black hole properties and horizon structure.

Contribution

It presents a novel rotating hairy black hole metric with a non-minimally coupled scalar field, deriving the scalar potential from the metric ansatz and analyzing horizon conditions.

Findings

The solution includes zero, one, or two horizons depending on parameters.

The scalar potential depends on two constants linked to mass and angular momentum.

Degenerates to known solutions for specific parameter choices.

Abstract

We present some novel rotating hairy black hole metric in $(2+1)$ dimensions, which is an exact solution to the field equations of the Einstein-scalar-AdS theory with a non-minimal coupling. The scalar potential is determined by the metric ansatz and consistency of the field equations and cannot be prescribed arbitrarily. In the simplified, critical case, the scalar potential contains two independent constant parameters, which are respectively related to the mass and angular momentum of the black hole in a particular way. As long as the angular momentum does not vanish, the metric can have zero, one or two horizons. The case with no horizon is physically uninteresting because of the curvature singularity lying at the origin. We identified the necessary conditions for at least one horizon to be present in the solution, which imposes some bound on the mass-angular momentum ratio. For some particular choice of parameters our solution degenerates into some previously known black hole solutions.