Viability of warm inflation with standard model interactions

The minimal warm inflation scenario proposed in Ref. [1] – featuring an axionlike inflaton coupled to Standard Model (SM) gluons via the standard interaction $\phi G\tilde{G}$ – offers a compelling bridge between inflationary dynamics and SM particle content. While the model retains only the inflaton as a beyond-SM field, its original analysis relied on some approximate treatments of warm inflation’s (WI) dynamics. Here, we revisit this scenario using WI2easy, a precision computational tool for WI dynamics [2], to rigorously evaluate the model’s viability and full range of model’s parameters compatible with the observational parameters. Overall, we find that the results of Ref. [1] hold, but with significant differences in the weak and strong dissipative regimes of WI.