Weak deflection angle of a dirty black hole

2020/03/31 by Reggie C. Pantig, Emmanuel T. Rodulfo · 3 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Black Holes and Theoretical Physics #Dark matter #Deflection (physics) #Deflection angle #Galaxy #Pulsars and Gravitational Waves Research #RADIUS #Schwarzschild radius #gr-qc

paper · pdf · doi:10.1016/j.cjph.2020.06.015

published as Chin. J. Phys. (2020) 66; 691-702 · 6 pages, 1 figure; expressions in section 4 simplified thoroughly; accepted for publication in Chinese Journal of Physics

openalex publication_date 2020/07/01 · openalex created_date 2020/07/10 · arxiv created 2020/07/19 · arxiv updated 2020/07/21 · openalex updated_date 2026/08/05

Abstract

In this paper, we present the weak deflection angle in a Schwarzschild black hole of mass m surrounded by the dark matter of mass M and thickness Δrs. The Gauss-Bonnet theorem, formulated for asymptotic spacetimes, is found to be ill-behaved in the third-order of 1/Δrs for very large Δrs. Using the finite-distance for the radial locations of the source and the receiver, we derived the expression for the weak deflection angle up to the third-order of 1/Δrs using Ishihara (et al.) method. The result showed that the required dark matter thickness is ∼23mM for the deviations in the weak deflection angle to occur. Such thickness requirement is better by a factor of 2 as compared to the deviations in the shadow radius (∼3mM). It implies that the use of the weak deflection angle in detecting dark matter effects in one’s galaxy is better than using any deviations in the shadow radius.

Citations

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Cited by

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• Shadow and weak deflection angle of extended uncertainty principle black hole surrounded with dark matter