Warm deformed $R^{2}$ inflation

TL;DR

This paper explores a warm inflation model based on a deformed $R^{2}$ gravity, deriving the potential and analyzing inflationary observables, which align well with Planck 2018 data, especially in the strong regime.

Contribution

The work introduces a warm inflation scenario with a slight deformation of $R^{2}$ gravity and constrains model parameters using latest observational data.

Findings

Model predictions for $n_s$ and $r$ match Planck 2018 constraints.

Constraints on the potential scale $U_0$ are obtained.

The strong regime of interaction is effectively analyzed.

Abstract

In this work, we study warm inflationary scenario based on a deformation of $R^{2}$ gravity. We start considering $R^{p}$ and assume $p=2(1+\delta)$ with $\delta\ll 1$ so that we simply obtain warm $R^{2}$ inflation when setting $\delta=0$. We then derive the potential in the Einstein frame and consider a dissipation parameter of the form $\Gamma = C_{1}T$ with $C_1$ being a coupling parameter. We focus only on the strong regime of which the interaction between inflaton and radiation fluid has been taken into account. We compute inflationary observables and constrain the parameters of our model using latest observational data reported by Planck. From our analysis, we discover that with proper choices of parameters the derived $n_s$ and $r$ are in good agreement with the Planck 2018 observational constraints. Particularly, we constrain the potential scale $U_{0}$ of the models.