Perturbations and non-Gaussianities in three-form inflationary   magnetogenesis
  We reconsider magnetogenesis in the context of three-form inflation, and its backreaction. In particular, we focus on first order perturbation theory during inflation and subsequent radiation era: we discuss the consistency of the perturbative approach, and elaborate on the possible non-Gaussian signatures of the model. 
Federico R. Urban and Tomi K. Koivisto
astro-ph.CO hep-ph hep-th