Off-equatorial deflections and gravitational lensing. II. In general stationary and axisymmetric spacetimes*
Year: 2024
Type: article
Abstract: In this work, we develop a general perturbative procedure to determine the off-equatorial plane deflections in the weak deflection limit in general stationary and axisymmetric spacetimes, enabling the existence of the generalized Carter constant. Deflections of both null and timelike rays, with the finite distance effect of the source and detector considered, are obtained as dual series of and . These deflections enable a set of exact gravitational lensing equations from which the apparent angular positions of the images are solved. The method and general results are then applied to the Kerr-Newmann, Kerr-Sen, and rotating Simpson-Visser spacetimes to study the effect of the spin and characteristic (effective) charge of the spacetimes and the source altitude on the deflection angles and image apparent angles. We find that, generally, both the spacetime spin and charge affect only the deflections from the second non-trivial order, whereas the source altitude influences the deflection from the leading order. Because of this, measuring the effects of the spacetime spin and charge from the apparent locations of the images in gravitational lensing in realistic scenarios is difficult. We also present the off-equatorial deflections in the rotating Bardeen, Hayward, Ghosh, and Tinchev black hole spacetimes.
Source: Chinese Physics C
Authors: Xinguang 信广 Ying 英, Junji 俊基 Jia 贾
Institution: Wuhan University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4405784095