New mechanism for the generation of primordial seeds for the cosmic magnetic fields

We discuss the inflationary production of magnetic seeds for the galactic dynamo through photon-graviphoton mixing, typical of extended models of local supersymmetry. An analysis of the allowed region in parameter space shows that such a mechanism is compatible with existing phenomelogical bounds on the vector mass and mixing parameter, but requires a large enough mixing that seems difficult to implement naturally in the context of a minimal supersymmetric scenario.