CMB constraints on $U(1)$ axion warm inflation

TL;DR

This paper introduces a warm inflation model driven by axion-like particles interacting with U(1) gauge fields, consistent with CMB data, and provides constraints on model parameters using cosmological codes.

Contribution

It extends warm inflation models by incorporating electromagnetic fluctuations and backreaction, offering a novel mechanism compatible with observations.

Findings

Model consistent with CMB observations

Constraints on axion decay constant f < M_pl

New insights into early universe thermal history

Abstract

In this work, we propose a model of warm inflation driven by axion-like particles interacting with $U(1)$ gauge fields, with implications for the early universe's thermal evolution. By extending traditional warm inflation models, we introduce a dissipation mechanism through the thermal fluctuations of electromagnetic fields, leading to a non-trivial backreaction on the inflaton's dynamics. Our results are consistent with CMB observations, even for a natural sub-Plankian axion decay constant $f<M_{\rm Pl}$. We present precise constraints on the model's free parameters, using CAMB and CosmoMC codes. These findings offer new insights into the thermal history of the universe and the nature of inflationary dynamics.