Derivative coupling of inflaton to $R^{(3)}$

TL;DR

This paper explores a novel inflation model involving a derivative coupling between the inflaton and the 3D Ricci scalar, showing it can align predictions with observational data.

Contribution

It introduces and analyzes the effects of a non-minimal derivative coupling $XR^{(3)}$ on inflationary perturbations, providing analytical corrections to power spectra.

Findings

For the $$ inflation model, predictions match observational best-fit regions.

Analytical calculations of $XR^{(3)}$ corrections to primordial spectra.

The model can reconcile inflation predictions with current cosmological data.

Abstract

We study the inflation scenario with the non-minimally derivative coupling $XR^{(3)}$, where $X=\nabla_\mu\phi \nabla^\mu\phi$, $\phi$ is the inflaton and $R^{(3)}$ is the 3-dimensional intrinsic Ricci scalar on the spacelike hypersurface, and analytically calculate the corrections of $XR^{(3)}$ on the power spectra of primordial perturbations. It is found that for the $\phi^2$ inflation model, the corresponding predictions can be driven to the best-fit region of the $n_s$-$r$ diagram.