Strong Gravitational Lensing for Photon Coupled to Weyl Tensor in Kiselev Black Hole

TL;DR

This paper investigates how photons coupled to Weyl tensor experience strong gravitational lensing and deflection in a Kiselev black hole, revealing dependencies on coupling, polarization, and black hole parameters.

Contribution

It extends previous work on Schwarzschild black holes to Kiselev black holes, analyzing photon motion, lensing, and shadows with Weyl tensor coupling effects.

Findings

Photon motion depends on coupling and polarization.

Existence of a critical coupling value for photon orbits.

Modified lensing angles and black hole shadows.

Abstract

The ambition of the present work is to highlight the phenomena of strong gravitational lensing and deflection angle for the photons coupling with Weyl tensor in a Kiselev black hole. Here, we have extended the prior work of Chen and Jing \cite{1} for Schwarzschild black hole to Kiselev black hole. For this purpose, the equation of motion for the photons coupled to Weyl tensor, null geodesic and equation of photon sphere in a Kiselev black hole spacetime have been formulated. It is found that the equation of motion of the photons depends not only on the coupling between photon and Weyl tensor, but also on the polarization direction of the photons. There is a critical value of the coupling parameter $\alpha$ for existence of the marginally circular photon orbit outside the event horizon, which depends on the parameters of black hole and the polarization direction of photons. Further, the polarization directions of coupled photon and the coupling parameter $\alpha$, both modify the features of the photon sphere, the angle of deflection and the functions $(\bar{a}$ and $\bar{b})$ for the strong gravitational lensing in Kiselev black hole spacetime. In addition to this, the observable gravitational lensing quantities and the shadows of the Kiselev black hole spacetime are presented in detail.