Classical Noncommutative Electrodynamics with External Source
Abstract
In a -noncommutative (NC) gauge field theory we extend the Seiberg-Witten (SW) map to include the (gauge-invariance-violating) external current and formulate - to the first order in the NC parameter - gauge-covariant classical field equations. We find solutions to these equations in the vacuum and in an external magnetic field, when the 4-current is a static electric charge of a finite size , restricted from below by the elementary length. We impose extra boundary conditions, which we use to rule out all singularities, included, from the solutions. The static charge proves to be a magnetic dipole, with its magnetic moment being inversely proportional to its size . The external magnetic field modifies the long-range Coulomb field and some electromagnetic form-factors. We also analyze the ambiguity in the SW map and show that at least to the order studied here it is equivalent to the ambiguity of adding a homogeneous solution to the current-conservation equation.
Cite
@article{arxiv.1106.0639,
title = {Classical Noncommutative Electrodynamics with External Source},
author = {T. C. Adorno and D. M. Gitman and A. E. Shabad and D. V. Vassilevich},
journal= {arXiv preprint arXiv:1106.0639},
year = {2011}
}