G-Curvaton

TL;DR

This paper introduces a G-curvaton model where a Galileon field generates curvature perturbations during inflation, analyzing its power spectrum, bispectrum, and non-Gaussianity, revealing potentially large non-Gaussian signals.

Contribution

It presents a novel G-curvaton model with detailed calculations of power spectrum and non-Gaussianity, highlighting its capacity for sizable non-Gaussian signals compared to previous models.

Findings

The G-curvaton model produces large local and equilateral non-Gaussianities up to order 10^2.

The power spectrum of the G-curvaton fluctuation is computed during inflation.

The model's non-Gaussianity depends on specific parameters, allowing for sizable signals.

Abstract

In this paper, we study a curvaton model where the curvaton is acted by Galileon field. We calculate the power spectrum of fluctuation of G-curvaton during inflation and discuss how it converts to the curvature perturbation after the end of inflation. We estimate the bispectrum of curvature perturbation induced, and show the dependence of non-Gaussianity on the parameters of model. It is found that our model can have sizable local and equilateral non-Gaussianities to up to ${\cal O}(10^2)$, which is illustrated by an explicit example.