Cosmological constraints on slow-roll inflation: an update

TL;DR

This paper updates constraints on slow-roll inflation models using recent cosmological data, examining extended scenarios with additional parameters and analyzing dataset impacts on model compatibility.

Contribution

It provides the first comprehensive analysis of slow-roll inflation constraints with multiple extended parameters and diverse datasets.

Findings

No evidence for scalar running or running of running from Planck 2018 data.

Preference for non-zero scalar running and running of running with ACT and WMAP data.

Dataset differences significantly affect inflationary model compatibility.

Abstract

In light of the most recent cosmological observations, we provide new updated constraints on the slow-roll inflation in different extended scenarios beyond the $\Lambda\rm{CDM}$ cosmological model. Along with the usual six parameters, we simultaneously vary different combinations of additional parameters, including the running of the scalar spectral index $\alpha_s$, its running of running $\beta_s$, the tensor amplitude $r$ and the spatial curvature $\Omega_k$. From the Planck 2018 data, we find no evidence for a scalar running or a running of running, while analyzing the Atacama Cosmology Telescope data combined with WMAP 9-years observations data we find a preference for non-zero $\alpha_s$ and $\beta_s$ at the level of 2.9$\sigma$ and 2.7$\sigma$, respectively. Anyway, this preference is reduced when the tensor amplitude can vary in the model or $\beta_s$ is fixed to zero. The upper bound on $r$ is only slightly affected by the additional parameters while the differences in the datasets can remarkably change the compatibility among the different inflationary models, sometimes leading to discordant conclusions.