A U(1) gauge theory turns, on physically motivated models of Quantum
Spacetime, into a U(∞) gauge theory, hence free classical
electrodynamics is no longer free and neutral fields may have electromagnetic
interactions. We discuss the last point for scalar fields, possibly describing
dark matter; we have in mind the gravitational collapse of binary systems or
future applications to self gravitating Bose-Einstein condensates as possible
sources of evidence of quantum gravitational phenomena. The effects so far
considered, however, seem too faint to be detectable at present.Comment: 14 page