Frequency Shifts of photons emitted from geodesics of nonlinear electromagnetic black holes

TL;DR

This paper investigates how non-linear electrodynamics influences the frequency shifts of photons emitted from particles orbiting black holes, revealing differences from linear models through specific black hole examples.

Contribution

It introduces the analysis of photon frequency shifts in black holes with non-linear electrodynamics, highlighting the effects of magnetic and electric factors on these shifts.

Findings

Frequency shifts differ between non-linear and linear electrodynamics black holes.

Magnetic and electric factors significantly modify photon frequency shifts.

Comparison of various black hole models illustrates the impact of non-linearity.

Abstract

We analyzed the frequency shifts of photons emitted from massive particles that move in stable geodesics around black holes with non-linear electrodynamics. The motion of the photon is modified by an effective metric when the Einstein gravity is coupled with non-linear electrodynamics. The kinematic shifts for photons are modified by the magnetic and electric factors that make the difference between the linear and non-linear electrodynamics. As an illustration, we present the frequency shifts of the photons for black holes with non-linear electrodynamics, two magnetic black holes, and two electric black holes, the Bardeen and Bronnikov black holes for the magnetic charge and the Born-Infeld and Dymnikova black holes for electric charge. These frequency shifts are compared with their linear electromagnetic counterpart.