C. Sivaram et Lcg. Deandrade, ASTROPHYSICAL LIMITS ON GAUGE-INVARIANCE BREAKING IN ELECTRODYNAMICS WITH TORSION, Astrophysics and space science, 201(1), 1993, pp. 121-123
General relativistic electrodynamics in a torsion background can give
rise to a situation where the photons can ahve a non-zero rest mass an
d magnetic moment. Astrophysical limits are used to constrain these pa
rameters.