Magnetically charged black holes from non-linear electrodynamics and the Event Horizon Telescope

TL;DR

This paper investigates how non-linear electrodynamics affects black hole shadows and uses Event Horizon Telescope data to set new limits on black hole magnetic charge, linking fundamental physics with astronomical observations.

Contribution

It introduces constraints on black hole magnetic charge by analyzing shadows in non-linear electrodynamics models compared to EHT observations.

Findings

Upper limits on black hole magnetic charge derived from shadow analysis

Comparison of NLED black hole shadows with M87* observations

Constraints on fundamental physics from astronomical data

Abstract

Non-linear electrodynamics (NLED) theories are well-motivated extensions of QED in the strong field regime, and have long been studied in the search for regular black hole (BH) solutions. We consider two well-studied and well-motivated NLED models coupled to General Relativity: the Euler-Heisenberg model and the Bronnikov model. After carefully accounting for the effective geometry induced by the NLED corrections, we determine the shadows of BHs within these two models. We then compare these to the shadow of the supermassive BH M87* recently imaged by the Event Horizon Telescope collaboration. In doing so, we are able to extract upper limits on the black hole magnetic charge, thus providing novel constraints on fundamental physics from this new extraordinary probe.