Double-well Inflation: observational constraints and theoretical implications

TL;DR

This paper evaluates the observational viability of the double-well inflation model with minimal and nonminimal couplings, comparing it to Starobinsky inflation, and explores its implications within the type-I seesaw mechanism.

Contribution

It provides a comprehensive analysis of the double-well inflation model's compatibility with current CMB data, including parameter constraints and comparison with established models.

Findings

Starobinsky inflation is statistically preferred over double-well models.

Constraints on the inflaton's vacuum expectation value and coupling amplitude are established.

The model's implications within the type-I seesaw mechanism are explored.

Abstract

We revisit the small field double-well inflationary model and investigate its observational viability in light of the current Cosmic Microwave Background data. In particular, considering scenarios with minimal and nonminimal coupling between the inflaton field and the Ricci scalar, we perform a Monte Carlo Markov chain analysis to probe the model's parameter space. We also investigate the consequences of the cosmological results in the canonical type-I seesaw mechanism context and obtain constraints on the vacuum expectation value of the inflaton field, together with the amplitude of the coupling to gravity in the nonminimal case. We employ a Bayesian procedure to compare the model's predictions with the Starobinsky inflationary scenario and find a strong statistical preference for the latter against the minimal and nonminimal coupled double-well scenario.