Reheating through the Higgs amplified by spinodal instabilities and gravitational creation of gravitons

TL;DR

This paper demonstrates that a positive non-minimal coupling of the Higgs field to gravity can address key issues in inflationary models, including graviton overproduction and curvature perturbation constraints, with implications for observational tests.

Contribution

It introduces a non-minimal Higgs-gravity coupling as a solution to inflationary reheating problems and discusses observational constraints on this coupling.

Findings

Non-minimal Higgs coupling alleviates graviton overproduction.

Constraints on coupling improve with CMB and large-scale structure data.

Addresses curvature perturbation overproduction in inflation models.

Abstract

It is shown that a positive non-minimal coupling of the Higgs field to gravity can solve the two problems in inflation models in which postinflationary universe is dominated by an energy with stiff equation of state such as a kination, namely, overproduction of gravitons in gravitational reheating scenario, and overproduction of curvature perturbation from Higgs condensation. Furthermore, we argue that the non-minimal coupling parameter can be constrained more stringently with the progress in observations of large-scale structure and cosmic microwave background.