Non-minimal α-attractor magnetogenesis with potential dependent couplings
Abstract
We investigate inflationary magnetogenesis driven by a non conformal coupling in the case of large-field α-attractor inspired models. We introduce potential-dependent electromagnetic coupling functions f(ϕ) that reproduce the scaling f∝ ap during slow roll. Starting from Starobinsky inflation, we analytically derive explicit couplings for (E)-model and (T)-model potentials. We then study how these functions affect electromagnetic amplification in the regime of non-minimal coupling between the inflaton field and the Ricci scalar ϕ2 R. In particular, we compare different values for the coupling strength ξ, accounting for electromagnetic backreaction and Schwinger pair production through the gradient expansion formalism. Our numerical results show that the non-minimal coupling affects the evolution of the electromagnetic sector and the resulting magnetic-field amplitude. We find that, within the analyzed configurations, minimally coupled and ξ>0 scenarios are compatible with the adopted CMB constraints, yielding conditional present-day magnetic-field estimates of order 10−23 G.
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BibTeX
@misc{marino2026nonminimal,
title = {{Non-minimal $α$-attractor magnetogenesis with potential dependent couplings}},
author = {Antonino G. Marino and Tommaso Mengoni},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.36228},
eprint = {2610.36228},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.36228},
}
RIS
TY - UNPB
TI - Non-minimal α-attractor magnetogenesis with potential dependent couplings
AU - Antonino G. Marino
AU - Tommaso Mengoni
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.36228
UR - https://arxiv.org/abs/2610.36228
AB - We investigate inflationary magnetogenesis driven by a non conformal coupling in the case of large-field α-attractor inspired models. We introduce potential-dependent electromagnetic coupling functions f(ϕ) that reproduce the scaling f∝ a^p during slow roll. Starting from Starobinsky inflation, we analytically derive explicit couplings for (E)-model and (T)-model potentials. We then study how these functions affect electromagnetic amplification in the regime of non-minimal coupling between the inflaton field and the Ricci scalar ϕ^2 R. In particular, we compare different values for the coupling strength ξ, accounting for electromagnetic backreaction and Schwinger pair production through the gradient expansion formalism. Our numerical results show that the non-minimal coupling affects the evolution of the electromagnetic sector and the resulting magnetic-field amplitude. We find that, within the analyzed configurations, minimally coupled and ξ>0 scenarios are compatible with the adopted CMB constraints, yielding conditional present-day magnetic-field estimates of order 10^−23 G.
ER -