Probing inflation with large-scale structure data: the contribution of information at small scales

TL;DR

Upcoming large-scale structure surveys like Euclid can significantly improve constraints on inflation models by utilizing small-scale information, potentially revealing features in the primordial spectrum beyond the slow-roll approximation.

Contribution

This study demonstrates how Euclid data can enhance constraints on inflation potentials, especially through small-scale features, using the WWI framework and different non-linear cut-off setups.

Findings

Euclid data improves constraints on inflation potential.

Realistic non-linear cut-off setup offers marginal gains over Conservative.

Euclid may detect oscillations in the primordial spectrum at small scales.

Abstract

Upcoming full-sky large-scale structure surveys such as Euclid can probe the primordial Universe. Using the specifications for the Euclid survey, we estimate the constraints on the inflation potential beyond slow-roll. We use mock Euclid and Planck data from fiducial cosmological models using the Wiggly Whipped Inflation (WWI) framework, which generates features in the primordial power spectrum. We include Euclid cosmic shear and galaxy clustering, with two setups (Conservative and Realistic) for the non-linear cut-off. We find that the addition of Euclid data gives an improvement in constraints in the WWI potential, with the Realistic setup providing marginal improvement over the Conservative for most models. This shows that Euclid may allow us to identify oscillations in the primordial spectrum present at intermediate to small scales.