Large-scale magnetic fields from inflation due to a CPT-even Chern–Simons-like term with Kalb–Ramond and scalar fields

Abstract

We investigate the generation of large-scale magnetic fields due to the breaking of the conformal invariance in the electromagnetic field through the CPT-even dimension-six Chern–Simons-like effective interaction with a fermion current by taking account of the dynamical Kalb–Ramond and scalar fields in inflationary cosmology. It is explicitly demonstrated that magnetic fields on 1 Mpc scale with the field strength of ∼10−9 G at the present time can be induced.