Clockwork inflation with non-minimal coupling

TL;DR

This paper proposes a clockwork mechanism to explain the small ratio of parameters in Higgs-like inflation with non-minimal coupling, avoiding the need for a large coupling and connecting inflation to observable low-energy physics.

Contribution

It introduces a clockwork framework for Higgs-like inflation with non-minimal coupling, providing a natural explanation for parameter ratios and linking inflation to Standard Model physics.

Findings

Clockwork mechanism suppresses the inflaton's quartic coupling exponentially.

Inflation can be achieved with a sub-GeV inflaton mass.

Reheating and inflaton lifetime have observable implications.

Abstract

We suggest a clockwork mechanism for a Higgs-like inflation with the non-minimal coupling term $\xi\phi^2 R$. The seemingly unnatural ratio of parameters, $\lambda/\xi^2 \sim 10^{-10}$ of the self quartic coupling of the inflaton, $\lambda$, and the non-minimal coupling, $\xi$, is understood by exponential suppression of $\lambda$ by the clockwork mechanism, instead of a large non-minimal coupling. The portal interaction between the inflaton and the Standard Model (SM) Higgs doublet is introduced as a source of reheating and the inflaton mass. Successful realization of inflation requires that the inflaton gets a mass around (sub) GeV scale, which would lead to observable consequences depending on reheating process and its lifetime.