Rotating black holes with primary scalar hair in beyond Horndeski gravity produce shadows whose diameter increases for negative Q and whose distortion increases for positive Q, with EHT bounds on M87* restricting but not ruling out the (a, Q) parameter space.
A Metric for Rapidly Spinning Black Holes Suitable for Strong-Field Tests of the No-Hair Theorem
7 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
According to the no-hair theorem, astrophysical black holes are uniquely characterized by their masses and spins and are described by the Kerr metric. Several parametric deviations from the Kerr metric have been suggested to study observational signatures in both the electromagnetic and gravitational-wave spectra that differ from the expected Kerr signals. Due to the no-hair theorem, however, such spacetimes cannot be regular everywhere outside the event horizons, if they are solutions to the Einstein field equations; they are often characterized by naked singularities or closed time-like loops in the regions of the spacetime that are accessible to an external observer. For observational tests of the no-hair theorem that involve phenomena in the vicinity of the circular photon orbit or the innermost stable circular orbit around a black hole, these pathologies limit the applicability of the metrics only to compact objects that do not spin rapidly. In this paper, we construct a Kerr-like metric which depends on a set of free parameters in addition to its mass and spin and which is regular everywhere outside of the event horizon. We derive expressions for the energy and angular momentum of a particle on a circular equatorial orbit around the black hole and compute the locations of the innermost stable circular orbit and the circular photon orbit. We demonstrate that these orbits change significantly for even moderate deviations from the Kerr metric. The properties of our metric make it an ideally suited spacetime to carry out strong-field tests of the no-hair theorem in the electromagnetic spectrum using the properties of accretion flows around astrophysical black holes of arbitrary spin.
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Exact solutions in Einstein-SU(2) sigma model yield black holes and branes with bumpy horizons stabilized by integer vorticity of superfluid pions.
Combining regular black hole metrics with memory burden suppresses evaporation and opens a 10^6-10^8 g PBH mass window that can comprise all dark matter.
Numerical simulations benchmark the eikonal and post-Kerr approximations for quasinormal modes in deformed Kerr spacetimes, quantifying their errors relative to expected observational precision.
Spinoptics calculations show parameter-dependent out-of-plane deflection angles for light in RZ and hairy black hole spacetimes, with assessment of mimicry between the models.
Theoretical investigation of black hole fragmentation possibilities beyond standard GR constraints, with relevance to primordial black holes and mergers.
citing papers explorer
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Rotating Black Holes with Primary Scalar Hair: Shadow Signatures in Beyond Horndeski Gravity
Rotating black holes with primary scalar hair in beyond Horndeski gravity produce shadows whose diameter increases for negative Q and whose distortion increases for positive Q, with EHT bounds on M87* restricting but not ruling out the (a, Q) parameter space.
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Exact black holes and black branes with bumpy horizons supported by superfluid pions
Exact solutions in Einstein-SU(2) sigma model yield black holes and branes with bumpy horizons stabilized by integer vorticity of superfluid pions.
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Memory burden effect of regular primordial black holes
Combining regular black hole metrics with memory burden suppresses evaporation and opens a 10^6-10^8 g PBH mass window that can comprise all dark matter.
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Confronting eikonal and post-Kerr methods with numerical evolution of scalar field perturbations in spacetimes beyond Kerr
Numerical simulations benchmark the eikonal and post-Kerr approximations for quasinormal modes in deformed Kerr spacetimes, quantifying their errors relative to expected observational precision.
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Light Deflection due to Spinoptic Effects in Parametrized and Spherically Symmetric Hairy Black Holes
Spinoptics calculations show parameter-dependent out-of-plane deflection angles for light in RZ and hairy black hole spacetimes, with assessment of mimicry between the models.
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When Black Holes Can Wear Pants
Theoretical investigation of black hole fragmentation possibilities beyond standard GR constraints, with relevance to primordial black holes and mergers.
- Perturbations in the parametrized wormhole spacetime and their related quasinormal modes