Bending of electromagnetic wave in an ultra-strong magnetic field

TL;DR

This paper investigates how ultra-strong magnetic fields, exceeding the critical value, influence the bending of light through nonlinear electrodynamics, with implications for astrophysical phenomena like magnetar lensing.

Contribution

It introduces a method to calculate light bending in supercritical magnetic fields using the one-loop effective action of QED, extending understanding of nonlinear QED effects.

Findings

Estimated light bending angles in magnetar magnetic fields.

Compared magnetic bending with gravitational lensing effects.

Highlighted potential for observing nonlinear QED phenomena.

Abstract

We consider the bending of light by nonlinear electrodynamics when the magnetic field $B$ exceeds the critical value $B_{\rm c}$. Using the index of refraction derived from the analytic series representation in one-loop effective action of QED, we found the trajectory and the bending angle of light in geometric optics. The angle bent by ultra-strong magnetic field of magnetar was estimated and compared with the gravitational bending. The result may be useful in studying the lensing, birefringence, and other nonlinear quantum electrodynamic effects above $B_{\rm c}$.