Instability and backreaction of massive spin-2 fields around black holes
Sep 10, 2023
10 pages
Published in:
- Phys.Rev.D 108 (2023) 12, 124048
- Published: Dec 15, 2023
e-Print:
- 2309.05096 [gr-qc]
DOI:
- 10.1103/PhysRevD.108.124048 (publication)
View in:
Citations per year
Abstract: (APS)
A massive spin-2 field can grow unstably around a black hole, giving rise to a potential probe of the existence of such fields. In this work, we use time-domain evolutions to study such instabilities. Considering the linear regime by solving the equations generically governing a massive tensor field on the background of a Kerr black hole, we find that black hole spin increases the growth rate and, most significantly, the mass range of the axisymmetric (azimuthal number ) instability, which takes the form of the Gregory-Laflamme black string instability for zero spin. We also consider the superradiant unstable modes with , extending previous results to higher spin-2 masses, black hole spins, and azimuthal numbers. We find that the superradiant modes grow slower than the modes, except for a narrow range of high spins and masses, with and 2 requiring a dimensionless black hole spin of to be dominant. Thus, in most of the parameter space, the backreaction of the instability must be taken into account when using black holes to constrain massive spin-2 fields. As a simple model of this, we consider nonlinear evolutions in quadratic gravity, in particular Einstein-Weyl gravity. We find that, depending on the initial perturbation, the black hole may approach zero mass with the curvature blowing up in finite time, or can saturate at a larger mass with a surrounding cloud of the ghost spin-2 field.Note:
- 10 pages, 7 figures; updated to match PRD version; includes link to linear instability data
- black hole: spin
- spin: high
- black string: stability
- black hole: Kerr
- symmetry: axial
- spin: 0
- field theory: tensor
- back reaction
- gravitation: higher-order
- higher-order: 2
References(89)
Figures(8)
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