Constant roll inflation in multifield models

TL;DR

This paper extends constant roll inflation models to multiple scalar fields, deriving exact solutions and analyzing their compatibility with observational data, revealing new dynamics and potential observational signatures.

Contribution

It introduces a multi-field constant roll inflation framework, derives exact solutions, and explores the behavior of adiabatic and entropy perturbations in these models.

Findings

Exact solutions similar to single-field models

Adiabatic field also constant rolls in one case

Models can fit Planck data with suitable parameters

Abstract

Constant roll inflation is analyzed in the presence of multi scalar fields which are assumed to be described by a constant roll rate each. The different cases are studied and the corresponding potentials are reconstructed. The exact solutions are obtained, which show a similar behaviour to the single scalar field model. For one of the cases analyzed in the paper, the so-called adiabatic field also constant rolls while entropy perturbations become null, while the second case may lead to non-adiabatic perturbations. Both cases can fit well the Planck data by assuming the appropriate values for the free parameters of the models.