A New Version of Dirac’s Æther and Its Cosmological Applications

We propose a new formulation for the Æther of Dirac based on a lagrangian approach. We analyse how the presence of a particular self-interaction term in the lagrangian lead us to a description of the æther as being a medium with conductivity which is governed by macroscopic Maxwell equations with a polarization tensor Mαβ depending on the vector potential. These results are then applied to the analysis of the amplification of the primordial magnetic induction in a curved background of Friedmann’s geometry.