Black hole scalarization induced by the spin -- 2+1 time evolution

TL;DR

This paper investigates spin-induced black hole scalarization in Gauss-Bonnet gravity through 2+1 time evolution of linearized scalar perturbations, confirming the instability regions and the emergence of scalarized rotating black holes.

Contribution

It provides a direct numerical 2+1 dimensional evolution approach to study spin-induced scalarization, complementing previous theoretical and analytical results.

Findings

Identifies instability regions for Kerr black holes leading to scalarization.

Confirms the formation of scalarized rotating black holes.

Provides a numerical method for analyzing black hole scalarization phenomena.

Abstract

The scalarization is a very interesting phenomena allowing to endow a compact object with scalar hair while leaving all the predictions in the weak field limit unaltered. In Gauss-Bonnet gravity the source of the scalar field can be the curvature of the space-time. It was recently shown that for a particular type of coupling function between the scalar field and the Gauss-Bonnet invariant, spin-induced black hole scalarization is possible. In the present paper we study this phenomenon by performing a 2+1 time evolution of the relevant linearized scalar field perturbation equation and examine the region where the Kerr black hole becomes unstable giving rise to new scalarized rotating black holes. This is more direct numerical approach to study the development of spin-induced scalarization and it can serve as an independent check of the previous results.