ACT Implications for Hilltop Inflation

TL;DR

This paper examines how recent Atacama Cosmology Telescope data impacts hilltop and hilltop-squared inflation models, showing significant parameter constraints especially for hilltop-squared models compared to previous Planck results.

Contribution

It provides a systematic analysis of the implications of recent observational data on specific inflation models, highlighting the differences from prior constraints.

Findings

Parameter ranges for models are significantly reduced with ACT data.

Hilltop-squared models face more dramatic implications than hilltop models.

Recent data shifts the spectral index, affecting model viability.

Abstract

We analyze in a systematic way the implications for the classes of hilltop and hilltop-squared inflation of the recent DR6 observations by the Atacama Cosmology Telescope collaboration. We find that the reported shift in the spectral index leads to parameter ranges for these models that are significantly reduced when compared to the results obtained from the {\sc Planck} observations. We mainly focus on the more dramatic implications for the hilltop-squared class, but along the way we also highlight the milder impact on the class of hilltop models.