Inflaton versus Curvaton in Higher Dimensional Gauge Theories

TL;DR

This paper develops a cosmological inflation model using higher-dimensional gauge theories, where scalar fields from extra dimensions act as inflaton and curvaton, producing observable non-Gaussianity and tensor-to-scalar ratios.

Contribution

It introduces a novel inflationary scenario based on 6D gauge theories with scalar fields from extra dimensions, analyzing their effects on cosmological perturbations.

Findings

Curvaton is subdominant for linear perturbations.

Significant non-Gaussianity is generated.

A sizable tensor-to-scalar ratio is predicted.

Abstract

We construct a model of cosmological inflation and perturbation based on the higher-dimensional gauge theory. The inflaton and curvaton are the scalar fields arising from the extra space components of the gauge field living in more than four dimensions. We take the six-dimensional (6D) Yang-Mills theory compactified on $T^2$ as a toy model, and apply the one-loop effective potential of the inflaton and the curvaton to the curvaton scenario. We have found that the curvaton is subdominant for the linear curvature perturbation, but that a significant non-Gaussianity and a sizable tensor to scalar ratio are generated.