Black hole accretion discs and screened scalar hair

TL;DR

This paper introduces a new method to analyze scalar field configurations around black holes with accretion discs, applicable to both Schwarzschild and Kerr black holes, with potential observational implications.

Contribution

It develops a novel approach using Weyl coordinates to compute scalar profiles around black holes with accretion discs for various models.

Findings

Scalar profiles around Schwarzschild and Kerr black holes are calculated.

The method enables analysis of scalar fields with large Compton wavelengths.

Potential observational effects of scalar hair are discussed.

Abstract

We present a novel way to investigate scalar field profiles around black holes with an accretion disc for a range of models where the Compton wavelength of the scalar is large compared to other length scales. By analysing the problem in "Weyl" coordinates, we are able to calculate the scalar profiles for accretion discs in the static Schwarzschild, as well as rotating Kerr, black holes. We comment on observational effects.