Effective field theories and inflationary magnetogenesis

The effective approach is applied to the analysis of inflationary magnetogenesis. Rather than assuming a particular underlying description, all the generally covariant terms potentially appearing with four space-time derivatives in the effective action have been included and weighted by inflaton-dependent couplings. The higher derivatives are suppressed by the negative powers of a typical mass scale whose specific values ultimately depend on the tensor to scalar ratio. During a quasi-de Sitter stage the corresponding corrections always lead to an asymmetry between the hypermagnetic and the hyperelectric susceptibilities. After presenting a general method for the estimate of the gauge power spectra, the obtained results are illustrated for generic models and also in the case of some non-generic scenarios where either the inflaton has some extra symmetry or the higher-order terms are potentially dominant. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The effective approach is applied to the analysis of inflationary magnetogenesis, considering generally covariant terms with four space-time derivatives and weightings by inflaton-dependent couplings. The higher derivatives are suppressed by negative powers of a typical mass scale. This leads to an asymmetry between hypermagnetic and hyperelectric susceptibilities during a quasi-de Sitter stage.