Scharnhorst effect for a general two-parameter lagrangian density

TL;DR

This paper investigates how electromagnetic wave propagation, governed by a general two-parameter Lagrangian including Euler-Heisenberg and Born-Infeld models, is influenced by boundary conditions imposed by parallel plates.

Contribution

It extends the analysis of the Scharnhorst effect to a broad class of nonlinear electrodynamics Lagrangians with various boundary conditions.

Findings

Propagation speed can be altered by boundary conditions and Lagrangian parameters.

Different plate configurations lead to distinct modifications of light speed.

The results generalize previous Scharnhorst effect studies to more complex models.

Abstract

We discuss how the propagation of electromagnetic fields described by a general two-parameter lagrangian, which contains the Euler-Heisenberg effective lagrangian and the Born-Infeld lagrangian as particular cases, is affected by a pair of parallel plates that impose boundary conditions in the quantized field. We consider three differents setups, namely: (i) two perfectly conducting plates; (ii) two infinitely permeable plates and (iii) a pair of plates in which one of them is a perfect conductor and the other has an infinite magnetic permeability.