Non-Gaussianity, Spectral Index and Tensor Modes in Mixed Inflaton and Curvaton Models

TL;DR

This paper explores how mixed inflaton and curvaton models can produce significant non-Gaussianity while remaining consistent with current observational constraints on spectral index and tensor modes, impacting inflationary model development.

Contribution

It analyzes the conditions under which mixed inflaton-curvaton models generate large non-Gaussianity compatible with observational data.

Findings

Large non-Gaussianity can be achieved in mixed models.

Models can match current spectral index and tensor mode constraints.

Implications for inflationary model-building are discussed.

Abstract

We study non-Gaussianity, the spectral index of primordial scalar fluctuations and tensor modes in models where fluctuations from the inflaton and the curvaton can both contribute to the present cosmic density fluctuations. Even though simple single-field inflation models generate only tiny non-Gaussianity, if we consider such a mixed scenario, large non-Gaussianity can be produced. Furthermore, we study the inflationary parameters such as the spectral index and the tensor-to-scalar ratio in this kind of models and discuss in what cases models predict the spectral index and tensor modes allowed by the current data while generating large non-Gaussianity, which may have many implications for model-buildings of the inflationary universe.