Viable inflationary magnetogenesis with helical coupling

Understand

We consider helical coupling to electromagnetism and present a simple scenario of evolution of the coupling function leading to a viable inflationary magnetogenesis without the problem of back-reaction.

• In this scenario, helical magnetic fields of strength of order up to $10^{- 7}\,\text{G}$, when extrapolated to the current epoch, can be generated in a narrow spectral band centered at any reasonable wavenumber by adjusting the model parameters.
• We discuss implications of this model for baryogenesis, which impose additional constraints on the strength and correlation length of magnetic field.