Effectively massive photons within Abelian Higgs galaxies

We demonstrate that photons emitted by spiral galaxies become effectively massive , if the latter are treated as macroscopic Abelian Higgs topological solitons. The rest mass of a photon is shown to be proportional to the squared amplitude of the Higgs field distribution representing a ‘background’ static cylindrically symmetric magnetic vorto‐source (‐sink). Because the amplitude increases in a monotonous fashion from zero at the center of a spiral to a fixed non‐zero value at its outer boundary, the rest mass (group velocity) of photons emitted at shorter distances from the galaxy' s center is smaller (greater) when compared to that of photons originating at larger distances. A rough estimate shows that for a spiral with a diameter of 60 kpc the maximum attainable mass of photon is of the order of 10 −60 g.