The Renormalizable Three-Term Polynomial Inflation with Large Tensor-to-Scalar Ratio

TL;DR

This paper explores renormalizable three-term polynomial inflation models within supersymmetric and non-supersymmetric frameworks, showing they can produce observable tensor-to-scalar ratios consistent with current data, and are testable in future experiments.

Contribution

It demonstrates that renormalizable three-term polynomial inflation models can be realized in supergravity with only two parameters and are compatible with observational data, including large tensor-to-scalar ratios.

Findings

Models can match Planck and BICEP2 data for spectral index and tensor-to-scalar ratio.

Spectral index running remains outside the 2σ range.

Models can saturate the upper bound on tensor-to-scalar ratio, r ≤ 0.11.

Abstract

We systematically study the renormalizable three-term polynomial inflation in the supersymmetric and non-supersymmetric models. The supersymmetric inflaton potentials can be realized in supergravity theory, and only have two independent parameters. We show that the general renormalizable supergravity model is equivalent to one kind of our supersymmetric models. We find that the spectral index and tensor-to-scalar ratio can be consistent with the Planck and BICEP2 results, but the running of spectral index is always out of the $2\sigma$ range. If we do not consider the BICEP2 experiment, these inflationary models can be highly consistent with the Planck observations and saturate its upper bound on the tensor-to-scalar ratio ($r \le 0.11$). Thus, our models can be tested at the future Planck and QUBIC experiments.