Chaotic Inflation RIDES Again

Abstract

Following the recent Atacama Cosmology Telescope (ACT) results, we revisit chaotic inflation based on a single complex scalar field with mass term $M^2|\Phi {|}^2$, which usually predicts a spectra index $n_s\approx 0.96$ but a too-large tensor to scalar ratio $r\approx 0.16$. With radiative corrections, the potential $M^2|\Phi {|}^2\ln \left(|\Phi {|}^2/{\Lambda }^2\right)$ induces spontaneous symmetry breaking near the scale $\Lambda$, yielding a Pseudo Nambu-Goldstone boson which can play the role of a quintessence field, hence radiative inflation and dark energy (RIDE). Including a non-minimal coupling to gravity $\xi |\Phi {|}^2{R}^2$ reduces $r$, allowing a good fit of the RIDE model to Planck data. Allowing a small additional quartic coupling correction $\lambda |\Phi {|}^4$ increases both $n_s$ and $r$, with a good fit to ACT data sets achieved for $\xi \approx 1$.

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