No Contact Terms for the Magnetic Field in Lorentz- and CPT-Violating Electrodynamics

TL;DR

This paper investigates whether Lorentz- and CPT-violating modifications to electrodynamics introduce contact terms in the magnetic field of moving charges, concluding that no such contact terms are present.

Contribution

It provides a detailed calculation showing the absence of contact terms in the magnetic field within Lorentz- and CPT-violating electrodynamics.

Findings

No delta-function contact terms in the magnetic field of a moving charge.

Unusual singularities in fields do not include contact terms.

Results clarify the nature of field singularities in modified electrodynamics.

Abstract

In a Lorentz- and CPT-violating modification of electrodynamics, the fields of a moving charge are known to have unusual singularities. This raises the question of whether the singular behavior may include $\delta$-function contact terms, similar to those that appear in the fields of idealized dipoles. However, by calculating the magnetic field of an infinite straight wire in this theory, we demonstrate that there are no such contact terms in the magnetic field of a moving point charge