New conservation laws for electromagnetic fields in gravity
Abstract
Description
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-Nordström 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.
12 pages, to be published in the proceedings "Symmetries and gravity in field theory", Workshop in honour of Prof. J. A. de Azcárraga, June 9-11, 2003, Salamanca (Spain), V Aldaya and J M Cerveró eds. (Ediciones Universidad de Salamanca, Salamanca)
12 pages, to be published in the proceedings "Symmetries and gravity in field theory", Workshop in honour of Prof. J. A. de Azcárraga, June 9-11, 2003, Salamanca (Spain), V Aldaya and J M Cerveró eds. (Ediciones Universidad de Salamanca, Salamanca)