Large-scale gauge spectra and pseudoscalar couplings
  It is shown that the slopes of the superhorizon hypermagnetic spectra
produced by the variation of the gauge couplings are practically unaffected by
the relative strength of the parity-breaking terms. A new method is proposed
for the estimate of the gauge power spectra in the presence of pseudoscalar
interactions during inflation. To corroborate the general results, various
concrete examples are explicitly analyzed. Since the large-scale gauge spectra
also determine the late-time magnetic fields it turns out that the pseudoscalar
contributions have little impact on the magnetogenesis requirement. Conversely
the parity-breaking terms crucially affect the gyrotropic spectra that may
seed, in certain models, the baryon asymmetry of the Universe. In the most
interesting regions of the parameter space the modes reentering prior to
symmetry breaking lead to a sufficiently large baryon asymmetry while the
magnetic power spectra associated with the modes reentering after symmetry
breaking may even be of the order of a few hundredths of a nG over typical
length scales comparable with the Mpc prior to the collapse of the protogalaxy.
From the viewpoint of the effective field theory description of magnetogenesis
scenarios these considerations hold generically for the whole class of
inflationary models where the inflaton is not constrained by any underlying
symmetry.
