Supergravity, α-attractors and primordial non-Gaussianity

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Published 11 October 2018 © 2018 IOP Publishing Ltd and Sissa Medialab
, , Citation Nicola Bartolo et al JCAP10(2018)017 DOI 10.1088/1475-7516/2018/10/017

1475-7516/2018/10/017

Abstract

We compute in detail how deviations from Einstein gravity at the inflation energy scale could appear as non-Gaussian features in the sky. To illustrate this we use multi-field α-attractor models in the framework of supergravity to realise inflation. We find no obvious obstacle for having choices of model's parameters that generate non-Gaussian features of the equilateral and local type at the Script O(1) level in the fNL non-Gaussianity parameter, thus being potentially detectable in future cosmological surveys. This non-Gaussianity has its origin in either the non-canonical kinetic term (which, in turn, is an immediate consequence of assuming an hyperbolic geometry of the moduli space), the interactions of the fields in the potential or the α-parameter, or a combination of these three. This opens up the exciting possibility of constraining the law of gravity at energy scales close to the Planck one.

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10.1088/1475-7516/2018/10/017