English

Supergravity, $\alpha$-attractors and primordial non-Gaussianity

Cosmology and Nongalactic Astrophysics 2018-11-14 v2 High Energy Physics - Theory

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\alpha-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 O\cal O(1) level in the fNLf_{\rm 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 α\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.

Keywords

Cite

@article{arxiv.1805.04269,
  title  = {Supergravity, $\alpha$-attractors and primordial non-Gaussianity},
  author = {Nicola Bartolo and Domenico Matteo Bianco and Raul Jimenez and Sabino Matarrese and Licia Verde},
  journal= {arXiv preprint arXiv:1805.04269},
  year   = {2018}
}

Comments

matches version published in JCAP; no major changes, conclusions unchanged

R2 v1 2026-06-23T01:51:43.717Z