Cosmological magnetic fields induced by metric perturbations after inflation

We consider the amplification of electromagnetic quantum vacuum fluctuations induced by the presence of metric perturbations at the end of inflation. We obtain the amplitude of the corresponding magnetic fields on super-Hubble scales and compare it with the requirements of the galactic dynamo mechanism for different values of the spectral index. Finally we discuss the possible effects of the dissipation of such fields in the form of gravitational waves.