Equilateral non-gaussianity and new physics on the horizon
Journal
Journal of Cosmology and Astroparticle Physics
Journal Volume
2011
Journal Issue
9
Date Issued
2011-09-01
Author(s)
Green, Daniel
Abstract
We examine the effective theory of single-field inflation in the limit where the scalar perturbations propagate with a small speed of sound. In this case the non-linearly realized time-translation symmetry of the Lagrangian implies large interactions, giving rise to primordial non-Gaussianities. When the non-Gaussianities are measurable, these interactions will become strongly coupled unless new physics appears close to the Hubble scale. Due to its proximity to the Hubble scale, the new physics is not necessarily decoupled from inflationary observables and can potentially affect the predictions of the model. To understand the types of corrections that may arise, we construct weakly-coupled completions of the theory and study their observational signatures. © 2011 IOP Publishing Ltd and SISSA.
Subjects
Ination | non-gaussianity | physics of the early universe
Type
journal article