Comparative of light propagation in Born-Infeld, Euler-Heisenberg and ModMax nonlinear electrodynamics

TL;DR

This paper compares light propagation in three nonlinear electrodynamics theories and uses black hole shadow observations to constrain their parameters, providing insights into their physical implications.

Contribution

It introduces a comparative analysis of light phase velocities and black hole shadows across Born-Infeld, Euler-Heisenberg, and Modified Maxwell theories.

Findings

Constraints on nonlinear parameters from black hole shadow observations.

Differences in light propagation characteristics among the three theories.

Effective metric approach to determine phase velocities.

Abstract

We compare light propagation through an intense electromagnetic background as described by three different nonlinear electrodynamics: Born-Infeld (BI), Euler-Heisenberg (EH), and Modified Maxwell (MM). We use the concept of effective metric to determine the phase velocities of a propagating wave from the BI and EH nonlinear electrodynamics and use them to set constraints on the MM nonlinear parameter. In a second part of the paper, we consider the black hole solutions of the nonlinear electrodynamics coupled with General Relativity and determine the shadows cast by the static black holes. Confronting the observations of the shadows of M87$^*$ and Sagittarius A$^*$ with our theoretical results allows us to set restrictions on the nonlinear parameters.