3 papers
hep-ph2026
Maxwell theories along the light track: Null Formalism in extended electrodynamics
Zhi Xiao, Bing Sun, Tao Zhu
We develop a differential-form approach to systematically derive the Newman-Penrose null-tetrad equations for Lorentz-violating extensions of Maxwell electrodynamics. The coordinat…
hep-ph2026
Constraints on birefringence-free photon theory within standard-model extension
Zhi Xiao, Hanlin Song, Bo-Qiang Ma
Constraints on the birefringence-free subset of Lorentz-violating (LV) operators are derived using 14 GRB photons in the GeV-band. These constraints target the isotropic $c_{(I)00}…
hep-ph2024
The asymptotic behavior of Lorentz-violating photon fields
Zhi Xiao, Hao Wang
In this work, we derive the Newman-Penrose formalism of Maxwell's equations using two approaches: differential forms and intrinsic derivatives. Denoting as , with…