Higgs inflation with non-minimal derivative coupling to gravity

TL;DR

This paper explores an extension of Higgs inflation where the Higgs field's kinetic term is non-minimally coupled to gravity, analyzing specific power-law couplings and their compatibility with observational data.

Contribution

It introduces a non-minimal kinetic coupling in Higgs inflation and identifies conditions under which it produces successful inflation consistent with Planck data.

Findings

Higgs boson can drive inflation for specific power-law couplings (n=2,1,0,-1).

Predictions for tensor-to-scalar ratio and spectral index align with Planck 2018 constraints.

The Higgs self-coupling at horizon crossing can vary between 10^{-7} and 0.3.

Abstract

We consider an extension of Higgs inflation in which the Higgs field is non-minimally coupled to gravity through its kinetic term. We analyzed power-law coupling functions with positive or negative integer power and found that the Higgs boson can drive a successful inflation only for the cases $n=2,1,0,-1$. Theoretical predictions for both tensor to scalar ratio $r$ and scalar spectral index $n_s$ are within the 2018 \textit{Planck} $95\%$ CL. The behavior of the self coupling $\lambda$ with respect to the scalar field at the horizon crossing was obtained, and It was found that it can take values in the interval $\lambda\sim (10^{-7}, 0.3)$.