Nonminimal coupling inflation with constant slow roll

TL;DR

This paper explores a modified inflationary model with non-minimal coupling using a novel first-order formalism, analyzing power-law and exponential couplings, and comparing results with CMB observations.

Contribution

It introduces a first-order formalism for constant-roll inflation with non-minimal coupling, applicable to various cosmological scenarios, and analyzes specific coupling functions.

Findings

The formalism simplifies equations of motion to first-order differential equations.

Power-law and exponential couplings are thoroughly analyzed in the inflationary context.

Model parameters are compared with CMB data to assess observational viability.

Abstract

We study a single field inflationary model modified by a non-minimal coupling term between the Ricci scalar $R$ and the scalar field $\varphi$ in the context of constant-roll inflation. The first-order formalism is used to analyse the constant-roll inflation instead of the standard methods used in the literature. In principle, the formalism considers two functions of the scalar field, $W=W(\varphi)$ and $Z=Z(\varphi)$, which lead to the reduction of the equations of motion to first-order differential equations. The approach can be applied to a wide range of cosmological situations since it directly relates the function $W$ with Hubble parameter $H$. We perform the inflationary analysis for power-law and exponential couplings, separately. Then, we investigate the features of constant-roll potentials as inflationary potentials. Finally, we compare the inflationary parameters of the models with the observations of CMB anisotropies in view of realize a physically motivated model.