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Main Authors: Huang, Yang, Fu, Xiangyun, Lu, Zhenyan, Qin, Xin
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2505.06999
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author Huang, Yang
Fu, Xiangyun
Lu, Zhenyan
Qin, Xin
author_facet Huang, Yang
Fu, Xiangyun
Lu, Zhenyan
Qin, Xin
contents Recently, we proposed a generalized Gibbons-Werner (GW) method for analyzing particle trajectories in rotating spacetimes, regardless of their asymptotic behavior [Huang \textit{et al.}, \href{https://iopscience.iop.org/article/10.1088/1475-7516/2024/01/013}{J. Cosmol. Astropart. Phys. 01(2024), 013}]. Using this method, we examine the impact of the cosmological constant ($Λ$) on the light deflection in rotating spacetimes within the framework of Kerr-de Sitter (KdS) geometry. Although Sultana previously calculated the deflection angle of light in KdS spacetime, our study advances this research in three aspects: (i) Orbit solution -- the light trajectory is derived by directly solving the original equation of motion (EOM) without intermediate processes. (ii) Positions of the source and observer -- the finite distances of the source and observer from the lens are explicitly considered, avoiding approximations. (iii) Staticity of the source and observer -- the Randers optical space is employed to resolve the staticity constraint. Through these refined considerations, we obtain a novel expression for the deflection angle of light in KdS spacetime, accurate to second-order in $Λ$, as well as in the mass (M) and spin parameter (a) of the central body. Furthermore, we discuss the discrepancies between our results and previous expressions. Finally, we evaluate the observational implications of our corrections relative to Sultana's work in the lensing systems of the Sun and Sgr A*, and show that they may become observable with forthcoming high-precision astronomical measurements.
format Preprint
id arxiv_https___arxiv_org_abs_2505_06999
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The influence of cosmological constant on light deflection in rotating spacetimes via the generalized Gibbons-Werner method
Huang, Yang
Fu, Xiangyun
Lu, Zhenyan
Qin, Xin
General Relativity and Quantum Cosmology
Recently, we proposed a generalized Gibbons-Werner (GW) method for analyzing particle trajectories in rotating spacetimes, regardless of their asymptotic behavior [Huang \textit{et al.}, \href{https://iopscience.iop.org/article/10.1088/1475-7516/2024/01/013}{J. Cosmol. Astropart. Phys. 01(2024), 013}]. Using this method, we examine the impact of the cosmological constant ($Λ$) on the light deflection in rotating spacetimes within the framework of Kerr-de Sitter (KdS) geometry. Although Sultana previously calculated the deflection angle of light in KdS spacetime, our study advances this research in three aspects: (i) Orbit solution -- the light trajectory is derived by directly solving the original equation of motion (EOM) without intermediate processes. (ii) Positions of the source and observer -- the finite distances of the source and observer from the lens are explicitly considered, avoiding approximations. (iii) Staticity of the source and observer -- the Randers optical space is employed to resolve the staticity constraint. Through these refined considerations, we obtain a novel expression for the deflection angle of light in KdS spacetime, accurate to second-order in $Λ$, as well as in the mass (M) and spin parameter (a) of the central body. Furthermore, we discuss the discrepancies between our results and previous expressions. Finally, we evaluate the observational implications of our corrections relative to Sultana's work in the lensing systems of the Sun and Sgr A*, and show that they may become observable with forthcoming high-precision astronomical measurements.
title The influence of cosmological constant on light deflection in rotating spacetimes via the generalized Gibbons-Werner method
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2505.06999