Inflationary attractors and radiative corrections in light of ACT data

TL;DR

Recent ACT data challenges many inflation models, but radiative corrections at sub-percent levels can reconcile $\xi$- and $\alpha$-attractor models with observations, raising questions about their predictive precision.

Contribution

This paper demonstrates that radiative corrections significantly impact inflationary model predictions, allowing models to align with new observational constraints.

Findings

Radiative corrections can shift inflation models into favored parameter regions.

Models remain flexible under small radiative corrections, affecting predictability.

ACT data constrains traditional inflation models, but corrections offer reconciliation.

Abstract

In light of the recent results from the Atacama Cosmology Telescope (ACT), which have provided a notable shift in the constraints on $(n_s, r)$ and placed several otherwise viable models of inflation in tension with the latest data, we investigate the possible effects that radiative corrections can have on $\xi$-attractor and $\alpha$-attractor models of inflation. These models, which share much in common with Starobinsky inflation, have likewise been put under pressure by these results. We find that percent (and even sub-percent) level radiative corrections can easily shift both of these classes of inflation models comfortably into the regions of parameter space favoured by the most recent constraints. However, the flexibility under such corrections calls into question to what extent it is possible to precisely pin down model-specific predictions for important cosmological observables.