Cosmological constraints on slow roll inflation: An update
Matteo Forconi, William Giarè, Eleonora Di Valentino, A. Melchiorri
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 $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ cosmological model. Along with the usual six parameters, we simultaneously vary different combinations of additional parameters, including the running of the scalar spectral index ${\ensuremath{\alpha}}_{s}$, its running of running ${\ensuremath{\beta}}_{s}$, the tensor amplitude $r$ and the spatial curvature ${\mathrm{\ensuremath{\Omega}}}_{k}$. 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 nonzero ${\ensuremath{\alpha}}_{s}$ and ${\ensuremath{\beta}}_{s}$ at the level of $2.9\ensuremath{\sigma}$ and $2.7\ensuremath{\sigma}$, respectively. Anyway, this preference is reduced when the tensor amplitude can vary in the model or ${\ensuremath{\beta}}_{s}$ 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.