The Inflationary Quartic Hilltop Model in a Modified Gravity and Its Comparison with the Observations

TL;DR

This paper explores a modified gravity approach to the quartic hilltop inflation model, analyzing its dynamics and compatibility with observational data, and finds that the modifications improve alignment with current cosmological measurements.

Contribution

It introduces a novel $F(\,\phi) T$ term in modified gravity to enhance the quartic hilltop inflation model's predictive accuracy.

Findings

The modified gravity model aligns well with Planck/BICEP/Keck data.

The $F(\,\phi) T$ term significantly affects inflationary parameters.

The model maintains consistency with original predictions.

Abstract

We investigate the inflation for the quartic hilltop model via a certain type of modified gravity. Precisely, we analyze the $F(\phi) T$ term in the Einstein's gravity to examine the quartic hilltop inflation model. $T$ is the trace of the energy-momentum tensor, and $\phi$ is the inflaton field. Next, we calculate the inflation dynamics for the foregoing model and obtain the slow-roll parameters, i.e., the scalar spectral index ``$n_s$'' and the tensor-to-scale ratio ``$r$'', which these parameters exhibit high sensitivity to the $F(\phi) T$ term. This modified form of the gravity is not only in accordance with the predictions of the original model but also allows for better prediction of the Planck/BICEP/Keck data.