Optical properties of Kerr-Newman spacetime in the presence of plasma

TL;DR

This paper investigates how plasma and black hole charge affect photon orbits and shadows in Kerr-Newman spacetime, revealing their influence on observable properties like black hole shadows and energy release.

Contribution

It provides a detailed analysis of null geodesics and shadow characteristics in Kerr-Newman spacetime with plasma, extending previous studies to include plasma effects and black hole charge.

Findings

Black hole charge and plasma parameters significantly alter photon orbits.

The size of the black hole shadow depends on plasma and charge effects.

Energy emission correlates with the shadow size.

Abstract

We have studied the null geodesics in the background of the Kerr-Newman black hole veiled by a plasma medium using the Hamilton-Jacobi method. The in uence of black hole's charge and plasma parameters on the effective potential and the generic photon orbits has been investigated. Furthermore, our discussion embodies the effects of black hole's charge, plasma and the inclination angle on the shadow cast by the gravity with and without the spin parameter. We examined the energy released from the black hole as a result of the thermal radiations, which exclusively depends on the size of the shadow. The angle of de ection of the massless particles is also explored considering a weak-field approximation.We present our results in juxtaposition to the analogous black holes in General Relativity, particularly the Schwarzschild and Kerr black hole.