Symmetry of polarization space and supplementary invariance of Maxwell's equations

The invariance of the two-potential formulation of Maxwell's equations relative to a set of transformations of the fields and potentials forming the group GL(2, c) GL(2, c), which narrows to the group GL(2, c) when the number of independent degrees of freedom characteristic of an electromagnetic field is taken into account, is established. The indicated invariance reflects a symmetry which is internally intrinsic to the polarization space of an electromagnetic field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 39–42, December, 1981.