Strong field gravitational lensing by hairy Kerr black holes

Abstract

Recent times witnessed a surge of interest in strong gravitational lensing by black holes due to the Event Horizon Telescope (EHT) results, which suggest comparing the black hole lensing in general relativity and modified gravity theories. This may help us to assess the phenomenological differences between these models. A Kerr black hole is also a solution to some alternative theories of gravity, while recently obtained modified Kerr black holes (hairy Kerr black holes), which evade the no-hair theorem, are due to additional sources from surrounding fluid, like dark matter, having conserved energy momentum tensor (EMT). These hairy Kerr black holes may also be solutions to an alternative theory of gravity. We generalize previous work on gravitational lensing by a Kerr black hole in the strong deflection limits to the hairy Kerr black holes, with a deviation parameter $\alpha$ and a primary hair ${\ell }_0$. Interestingly, the deflection coefficient $\bar{a}$ increases and decreases with increasing ${\ell }_0$ and $\alpha$ respectively. $\bar{b}$ shows opposite behaviour with ${\ell }_0$ and $\alpha$. We also find that the deflection angle ${\alpha }_D$, angular position ${\theta }_{\infty }$ and $u_m$ decrease, but angular separation $s$ increases with $\alpha$. We compare our results with those for Kerr black holes, and also apply the formalism to discuss the astrophysical consequences in the context of the supermassive black holes Sgr A* and M87*. We observe that the deviations of the angular positions from that of the Kerr black hole are not more than $2.6\mu$as for Sgr A* and $1.96\mu$as for M87*, which are unlikely to be resolved by the current EHT observations.

17 pages, 7 figures, 8 tables, minor typos corrected, accepted in Phys. Rev. D

References in corpus (19)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• Rotating regular black holes
• Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities
• Generating rotating regular black hole solutions without complexification
• Spontaneously scalarised Kerr black holes
• Searching Exact Solutions for Compact Stars in Braneworld: a conjecture
• Lensing by Kerr Black Holes
• Thin accretion disks in stationary axisymmetric wormhole spacetimes
• Strong field gravitational lensing in the deformed Hǒrava-Lifshitz black hole
• Shadow cast and deflection of light by charged rotating regular black holes
• Deflection angle in the strong deflection limit in a general asymptotically flat, static, spherically symmetric spacetime
• A comparison of approximate gravitational lens equations and a proposal for an improved new one
• Gravitational decoupling for axially symmetric systems and rotating black holes
• Braneworld black hole gravitational lens: Strong field limit analysis
• Gravitational Lensing by Spinning Black Holes in Astrophysics, and in the Movie Interstellar
• Testing Rotating Regular Metrics as Candidates for Astrophysical Black Holes
• Parameters estimation and strong gravitational lensing of nonsingular Kerr-Sen black holes
• Optical caustics of Kerr spacetime: the full structure

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