Curvaton with nonminimal derivative coupling to gravity

TL;DR

This paper introduces a curvaton model with nonminimal derivative coupling to gravity, enabling scale-invariant perturbations across various background equations-of-state, and explores related tensor and non-Gaussian perturbations.

Contribution

It presents a novel curvaton model with nonminimal derivative coupling that achieves scale invariance regardless of background equation-of-state values.

Findings

Scale-invariance achieved for arbitrary nearly constant equation-of-state.

Analysis of tensor perturbations and non-Gaussianities.

Discussion of adiabatic perturbations transferred during curvaton decay.

Abstract

We show a curvaton model, in which the curvaton has a nonminimal derivative coupling to gravity. Thanks to such a coupling, we find that the scale-invariance of the perturbations can be achieved for arbitrary values of the equation-of-state of background, provided that it is nearly a constant. We also discussed about tensor perturbations, the local non-Gaussianities generated by the nonminimal derivative coupling curvaton model, as well as the adiabatic perturbations which are transferred from the field perturbations during the curvaton decay.