We compute in detail how deviations from Einstein gravity at the inflination energy scale could appear as non-Gaussian features in the sky. To illustrate this we use multi-field alpha-attractor models in the framework of supergravity to realise in ination. 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 O (1) level in the f(NL) 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 alpha-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.
Supergravity, α-attractors and primordial non-Gaussianity
Bartolo Nicola;Matarrese Sabino;
2018
Abstract
We compute in detail how deviations from Einstein gravity at the inflination energy scale could appear as non-Gaussian features in the sky. To illustrate this we use multi-field alpha-attractor models in the framework of supergravity to realise in ination. 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 O (1) level in the f(NL) 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 alpha-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.Pubblicazioni consigliate
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