Baryogenesis, magnetogenesis and the strength of anomalous interactions

TL;DR

This paper explores how evolving gauge couplings and anomalous interactions during inflation influence hypermagnetic gyrotropy and baryon asymmetry, with implications for primordial magnetic fields and matter-antimatter imbalance.

Contribution

It provides a detailed analysis of hypermagnetic gyrotropy production under evolving gauge couplings and anomalous interactions, highlighting constraints and potential observational signatures.

Findings

Hypermagnetic gyrotropy production is sensitive to the strength of anomalous interactions.

Approximate duality symmetry constrains the late-time hypermagnetic spectra.

Parameter space regions can produce baryon asymmetry close to observed values.

Abstract

The production of the hypermagnetic gyrotropy is investigated under the assumption that the gauge coupling smoothly evolves during a quasi-de Sitter phase and then flattens out in the radiation epoch by always remaining perturbative. In the plane defined by the strength of the anomalous interactions and by the rate of evolution of the gauge coupling the actual weight of the pseudoscalar interactions turns out to be always rather modest if major deviations from the homogeneity are to be avoided during the inflationary phase. Even if the gauge power spectra are related by duality only in the absence of anomalous contributions, an approximate duality symmetry constrains the late-time form of the hypermagnetic power spectra. Since the hypermagnetic gyrotropy associated with the modes reentering prior to the phase transition must be released into fermions later on, the portions of the parameter space where the obtained baryon asymmetry is close to the observed value are the most relevant for the present ends. For the same range of parameters 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.