Gravity seminar - Bogdan Ganchev Seminar

We present a numerical analysis of the stability properties of the black holes with scalar hair con-
structed by Herdeiro and Radu. We prove the existence of a novel gauge where the scalar field
perturbations decouple from the metric perturbations, and analyse the resulting quasinormal mode
spectrum. We find unstable modes with characteristic growth rates which for uniformly small hair
are almost identical to those of a massive scalar field on a fixed Kerr background.