http://arxiv.org/abs/2210.07050
We propose a novel mechanism for significantly enhancing the amplitude of primordial electromagnetic fields during inflation. Similar to existing proposals, our idea is based on parametric resonance effects due to conformal-symmetry-breaking coupling of the gauge field and the inflaton. Our proposed scenario, however, significantly differs from previously studied models, and avoids their shortcomings. We, particularly, construct a viable system where the gauge field is exponentially amplified on super-horizon scales, therefore evading the no-go theorem formulated on the basis of widely encountered drastic back-reaction of the magnetic field energy on the inflationary background. We compute the spectrum of the produced magnetic fields and demonstrate the compatibility with current observational constraints.
M. Sasaki, V. Vardanyan and V. Yingcharoenrat
Fri, 14 Oct 22
32/75
Comments: 10 pages, 6 figures