How short can stationary charged scalar hair be?
Abstract
It is by now well established that charged rotating Kerr-Newman black holes can support bound-state charged-matter configurations which are made of minimally coupled massive-scalar fields. We here prove that the externally supported stationary charged scalar configurations cannot be arbitrarily compact. In particular, for linearized-charged-massive-scalar fields supported by charged rotating near-extremal Kerr-Newman black holes, we derive the remarkably compact lower bound (rfield-r+)/(r+-r-)>1 /s2 on the effective lengths of the external charged scalar "clouds" [here rfield is the radial peak location of the stationary scalar configuration, and {s ≡J /M2,r±} are, respectively, the dimensionless angular momentum and the horizon radii of the central supporting Kerr-Newman black hole]. Remarkably, this lower bound is universal in the sense that it is independent of the physical parameters (proper mass, electric charge, and angular momentum) of the supported charged scalar fields.
- Publication:
-
Physical Review D
- Pub Date:
- January 2022
- DOI:
- 10.1103/PhysRevD.105.024061
- arXiv:
- arXiv:2206.14819
- Bibcode:
- 2022PhRvD.105b4061H
- Keywords:
-
- General Relativity and Quantum Cosmology;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Theory
- E-Print:
- 8 pages