Spin-charge induced scalarization of Kerr-Newman black-hole spacetimes

Abstract

It has recently been demonstrated that Reissner-Nordström black holes in composed Einstein-Maxwell-scalar field theories can support static scalar field configurations with a non-minimal negative coupling to the Maxwell electromagnetic invariant of the charged spacetime. We here reveal the physically interesting fact that scalar field configurations with a non-minimal {\it positive} coupling to the spatially-dependent Maxwell electromagnetic invariant $\mathcal{F}\equiv F_{\mu \nu }{F}^{\mu \nu }$ can also be supported in black-hole spacetimes. Intriguingly, it is explicitly proved that the positive-coupling black-hole spontaneous scalarization phenomenon is induced by a non-zero combination $a\cdot Q\ne 0$ of {\it both} the spin $a\equiv J/M$ and the electric charge $Q$ of the central supporting black hole. Using analytical techniques we prove that the regime of existence of the positive-coupling spontaneous scalarization phenomenon of Kerr-Newman black holes with horizon radius $r_{+}(M,a,Q)$ and a non-zero electric charge $Q$ (which, in principle, may be arbitrarily small) is determined by the {\it critical onset line} $(a/r_{+}{)}_{\text{critical}}=\sqrt{2}-1$. In particular, spinning and charged Kerr-Newman black holes in the composed Einstein-Maxwell-scalar field theory are spontaneously scalarized by the positively coupled fields in the dimensionless charge regime $0<\frac{Q}{M}\le \sqrt{2\sqrt{2}-2}$ if their dimensionless spin parameters lie above the critical onset line $\frac{a(Q)}{M}\ge [\frac{a(Q)}{M}{]}_{\text{critical}}=\frac{1+\sqrt{1-2(2-\sqrt{2}){(Q/M)}^2}}{2\sqrt{2}}$.

7 pages. Submitted on 14 Jun 2022

References in corpus (6)

• Spontaneously scalarised Kerr black holes
• Kerr-Newman black holes with stationary charged scalar clouds
• Stability of highly-charged Reissner-Nordström black holes to charged scalar perturbations
• No nonminimally coupled massless scalar hair for spherically symmetric neutral black holes
• Reissner-Nordström black holes supporting non-minimally coupled massive scalar field configurations
• Infinitesimally thin static scalar shells surrounding charged Gauss-Bonnet black holes

Cited by in corpus (5)

• Spin-Charge induced spontaneous scalarization of Kerr-Newman black holes
• Mixed scalarization of charged black holes: from spontaneous to non-linear scalarization
• Black hole scalarizations induced by parity violations
• Charged Gauss-Bonnet black holes supporting non-minimally coupled scalar clouds: Analytic treatment in the near-critical regime
• Novel black holes with scalar hair in the Einstein-Maxwell-Scalar Theory with positive coupling