Analytical study of gravitational lensing in Kerr-Newman black-bounce spacetime
Source
arXiv
ISSN
2331-8422
Date Issued
2022-01-01
Author(s)
Ghosh, Saptaswa
Bhattacharyya, Arpan
Abstract
We investigate the equatorial deflection angle of light rays propagating in Kerr-Newman black-bounce spacetime. Furthermore, we analyze the light ray trajectories and derive a closed-form formula for deflection angle in terms of elliptic integrals. The deflection angle increases with the decrease of charge and regularisation parameter for a particular impact parameter. We also study the strong field limit of the deflection angle. Using this strong deflection angle formula and lens equation, we find the radius of the first Einstein ring and study its dependence on the charge and the regularisation parameter. We demonstrate that the charge has a robust effect on the size of the Einstein rings, but the effect of the regularization parameter on the ring size is negligible. These results directly affect the observational appearance of the Kerr-Newman black-bounce.
Subjects
Deflection
Spacetime
Trajectories
Regularisation
Kerr-Newman
