Spin-induced scalarization and magnetic fields

In the presence of certain non-minimal couplings between a scalar field and Gauss-Bonnet curvature invariant, Kerr black holes can scalarize, as long they are spinning fast enough. This provides distinctive violation hypothesis, occurring only for some high spin range. this paper we assess if strong magnetic fields, that may exist in vicinity astrophysical holes, could facilitate effect, by bringing down threshold scalarization. inquiry is motivated fact self-gravitating themselves, also promote "spin-induced" Nonetheless, show \textit{vicinity horizon} effect $B$ on hole mass $M$, up to $BM\lesssim 1$, works \textit{against} spin-induced scalarization, requiring larger dimensionless $j$ from hole. A geometric interpretation result suggested, terms effects rotation $vs.$ fields horizon geometry.