Reanalyzing the upper limit on the tensor-to-scalar perturbation ratio r_T in a quartic potential inflationary model

TL;DR

This paper investigates how lifting vacuum degeneracy in a quartic inflationary model affects the tensor-to-scalar ratio, showing it can meet observational limits when starting near the local maximum.

Contribution

It demonstrates that non-degenerate quartic potentials can satisfy Planck constraints on r_T by considering initial conditions near the local maximum.

Findings

Removing degeneracy allows the model to meet r_T constraints.

Starting near the local maximum is crucial for compatibility.

Scalar power spectrum and non-Gaussianity are computed.

Abstract

We study the polynomial chaotic inflation model with a single scalar field in a double well quartic potential which has recently been shown to be consistent with Planck data. In particular, we study the effects of lifting the degeneracy between the two vacua on the inflationary observables, i.e. spectral index n_s and tensor-to-scalar perturbation ratio r_T. We find that removing the degeneracy allows the model to satisfy the upper limit constraints on r_T from Planck data, provided the field starts near the local maximum. We also calculate the scalar power spectrum and non-Gaussianity parameter f_NL for the primordial scalar perturbations in this model.