The shadow of M87* black hole within rational nonlinear electrodynamics

TL;DR

This paper investigates the shadow of a regular magnetized black hole within rational nonlinear electrodynamics, comparing theoretical predictions with the observed shadow of M87* to suggest it could be a non-singular black hole.

Contribution

It introduces a model of regular magnetized black holes in nonlinear electrodynamics and compares their shadow sizes with the M87* observations, proposing a new interpretation of the black hole's nature.

Findings

The shadow size of the modeled black hole closely matches M87*'s observed shadow.

Super-massive M87* can be interpreted as a regular, non-singular magnetized black hole.

The model provides a potential electromagnetic explanation for the black hole's properties.

Abstract

We consider rational nonlinear electrodynamics with the Lagrangian ${\cal L} = -{\cal F}/(1+2\beta{\cal F})$ (${\cal F}=(1/4)F_{\mu\nu}F^{\mu\nu}$ is the Lorentz-invariant), proposed in [63], coupled to General Relativity. The effective geometry induced by nonlinear electrodynamics corrections are found. We determine shadow's size of regular non-rotating magnetic black holes and compare them with the shadow size of the super-massive M87* black hole imaged by the Event Horizon Telescope collaboration. Assuming that the black hole mass has a pure electromagnetic nature, we obtain the black hole magnetic charge. The size of the shadow obtained is very close to the shadow size of non-regular neutral Schwarzschild black holes. As a result, we can interpret the super-massive M87* black hole as a regular (without singularities) magnetized black hole.