Warm Inflation with the Standard Model
Abstract
We show for the first time that warm inflation is feasible with Standard Model (SM) gauge interactions alone. Our model consists of a minimal extension of the SM by a single scalar inflaton field with an axion-like coupling to gluons and a monomial potential. The effects of light fermions, which were previously argued to render warm inflation with the SM impossible, are alleviated by Hubble dilution of their chiral chemical potentials. Our model only features one adjustable combination of parameters and accommodates all inflationary observables. We briefly discuss implications for axion experiments, dark matter, and the strong CP-problem.
Cite
@article{arxiv.2503.18829,
title = {Warm Inflation with the Standard Model},
author = {Kim V. Berghaus and Marco Drewes and Sebastian Zell},
journal= {arXiv preprint arXiv:2503.18829},
year = {2025}
}
Comments
7 pages, 1 figure, 1 table; v2: Reduced uncertainty in Figure 1 by including computation of $N_*$. Added paragraph at end of appendix. v3: Improved calculation of CMB observables. Matches journal version to appear in Physical Review Letters