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

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.