Scale-dependence of Non-Gaussianity in the Curvaton Model

TL;DR

This paper explores how the scale-dependence of non-Gaussianity parameters in the self-interacting curvaton model can be observed and used to constrain model parameters with future CMB experiments, providing a potential way to fully determine the model.

Contribution

It demonstrates that the spectral index of f_NL can be observable and, combined with g_NL, can fully fix the self-interacting curvaton model parameters.

Findings

n_{f_NL} can be observable by future CMB experiments

g_NL scale-dependence offers a complementary probe

Model parameters can be fully constrained by observations

Abstract

We investigate the scale-dependence of f_NL in the self-interacting curvaton model. We show that the scale-dependence, encoded in the spectral index n_{f_NL}, can be observable by future cosmic microwave background observations, such as CMBpol, in a significant part of the parameter space of the model. We point out that together with information about the trispectrum g_NL, the self-interacting curvaton model parameters could be completely fixed by observations. We also discuss the scale-dependence of g_NL and its implications for the curvaton model, arguing that it could provide a complementary probe in cases where the theoretical value of n_{f_NL} is below observational sensitivity.