Tornkvist, Ola and Davis, Anne-Christine and Dimopoulos, Konstantinos and Prokopec, Tomislav (2000) Large scale primordial magnetic fields from inflation and preheating. In: COSMOLOGY AND PARTICLE PHYSICS: CAPP 2000: Proceedings :. American Institute of Physics, Melville, N.Y., pp. 443-446.
Abstract
We consider models in which the (transverse) photon mass is non-zero during inflation and drops to zero non-adiabatically at the end of inflation. Through this process, vacuum fluctuations of the photon field are converted into physical, long-wavelength modes with high amplitude. The resulting spectrum of the field strength is approximately B_l ~ 1/l, where l is the relevant coherence scale. With a reasonable model of field evolution we obtain, on comoving galactic scales, a magnetic field strong enough to seed a dynamo mechanism and generate the observed galactic magnetic fields.