Constant-roll approach to non-canonical inflation

TL;DR

This paper explores constant-roll inflation with a non-canonical scalar field, deriving exact solutions and showing that the model can align well with observational data for specific parameter choices.

Contribution

It introduces a constant-roll approach to non-canonical inflation, deriving modified perturbation parameters and demonstrating compatibility with observations.

Findings

Modified scalar spectral index and amplitude due to non-canonical kinetic term

Exact solutions for the Hubble parameter under constant-roll conditions

Model's attractor behavior supports observational consistency

Abstract

The scenario of constant-roll inflation is studied where the inflaton is a scalar field with modified kinetic term, known as non-canonical scalar field. This modification leads to some changes in the slow-roll parameters, and also by taking the second slow-roll parameter as a constant, the differential equation for the Hubble parameter is altered as well. Assuming $\eta=\beta$ and reconsidering the perturbation equations makes it clear that there should be some modified terms in the scalar spectral index and amplitude of scalar perturbations. After finding the exact solution, the main perturbation parameters are obtained at the horizon crossing time. Then by plotting the $r-n_s$ diagram it is shown that for some specific values of $\beta$ one could find a good agreement with observational data. In addition, considering the attractor behavior of the model leads to this result that this feature could be appropriately satisfied.