Gravitational instabilities of superspinars

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.044009· OSTI ID:21420946

Pani, Paolo; Barausse, Enrico; Berti, Emanuele; Cardoso, Vitor ^[1]

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1. Dipartimento di Fisica, Universita di Cagliari, and INFN sezione di Cagliari, Cittadella Universitaria 09042 Monserrato (Italy)

Superspinars are ultracompact objects whose mass M and angular momentum J violate the Kerr bound (cJ/GM{sup 2}>1). Recent studies analyzed the observable consequences of gravitational lensing and accretion around superspinars in astrophysical scenarios. In this paper we investigate the dynamical stability of superspinars to gravitational perturbations, considering either purely reflecting or perfectly absorbing boundary conditions at the 'surface' of the superspinar. We find that these objects are unstable independently of the boundary conditions, and that the instability is strongest for relatively small values of the spin. Also, we give a physical interpretation of the various instabilities that we find. Our results (together with the well-known fact that accretion tends to spin superspinars down) imply that superspinars are very unlikely astrophysical alternatives to black holes.

• OSTI ID: 21420946
• Journal Information: Physical Review. D, Particles Fields, Vol. 82, Issue 4; Other Information: DOI: 10.1103/PhysRevD.82.044009; (c) 2010 American Institute of Physics; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
BLACK HOLES
BOUNDARY CONDITIONS
DISTURBANCES
GRAVITATIONAL INSTABILITY
GRAVITATIONAL LENSES
KERR FIELD
MASS
PERTURBATION THEORY
SPIN
STABILITY
ANGULAR MOMENTUM
GRAVITATIONAL FIELDS
INSTABILITY
LENSES
PARTICLE PROPERTIES
PHYSICS
PLASMA INSTABILITY