Eikonal approximation, Finsler structures, and implications for Lorentz-violating photons in weak gravitational fields

Understand

The current article shall contribute to understanding the classical analogue of the minimal photon sector in the Lorentz-violating Standard-Model Extension (SME).

• It is supposed to complement all studies performed on classical point-particle equivalents of SME fermions.
• The classical analogue of a photon is not a massive particle being described by a usual equation of motion, but a geometric ray underlying the eikonal equation.
• The first part of the paper will set up the necessary tools to understand this correspondence for interesting cases of the minimal SME photon sector.