New conservation laws for electromagnetic fields in gravity
Abstract
A recently found (gr-qc/0303036) 2-index, symmetric, trace-free, divergence-free tensor is introduced for arbitrary source-free electromagnetic fields. The tensor can be constructed for any test Maxwell field in Einstein spaces (including proper vacuum), and more importantly for any Einstein-Maxwell spacetime. The tensor is explicitly given and analyzed in some special situations, such as general null electromagnetic fields, Reissner-Nordstr\"om solution, or classical electrodynamics. We present an explicit example where the conserved currents derived from the energy-momentum tensor using symmetries are trivial, but those derived from the new tensor are not.
Cite
@article{arxiv.gr-qc/0311033,
title = {New conservation laws for electromagnetic fields in gravity},
author = {José M. M. Senovilla},
journal= {arXiv preprint arXiv:gr-qc/0311033},
year = {2007}
}
Comments
12 pages, to be published in the proceedings "Symmetries and gravity in field theory", Workshop in honour of Prof. J. A. de Azc\'arraga, June 9-11, 2003, Salamanca (Spain), V Aldaya and J M Cerver\'o eds. (Ediciones Universidad de Salamanca, Salamanca)