The electromagnetic field equations for moving media

TL;DR

This paper develops a generalized formulation of electromagnetic field equations for moving media using 4D geometric quantities, revealing differences from traditional Maxwell's equations with 3-vectors.

Contribution

It introduces a novel 4D geometric approach to electromagnetism in moving media, incorporating observer and medium velocities, and compares it with classical Maxwell's equations.

Findings

Maxwell's equations with 3-vectors are not equivalent to the 4D geometric field equations.

The new formulation unifies Ampère-Maxwell and Gauss's laws into a single law.

The approach explicitly includes velocities of media and observers in the equations.

Abstract

In this paper a formulation of the field equation for moving media is developed by the generalization of an axiomatic geometric formulation of the electromagnetism in vacuum (Ivezi\'{c} T 2005 Found. Phys. Lett. 18 401. First, the field equations with bivectors F(x) and \mathcal{M}(x) are presented and then these equations are written with vectors E(x), B(x), P(x) and M(x). The latter ones contain both the velocity vector u of a moving medium and the velocity vector v of the observers who measure E and B fields. They do not appear in the entire previous literature. All these equations are written in the standard basis and compared with Maxwell's equations with 3-vectors. In this approach the Amp\`{e}r-Maxwell law and Gauss's law are inseparably connected in one law and the same happens with Faraday's law and the law that expresses the absence of magnetic charge. It is shown that Maxwell's equations with 3-vectors and our field equations with 4D geometric quantities are not equivalent in the 4D spacetime.