Clockwork Inflation

TL;DR

This paper explores the application of the clockwork mechanism in inflationary models, showing it can produce flat potentials and suppress tensor modes, thus offering new ways to realize inflation without fine-tuning.

Contribution

It demonstrates how the clockwork mechanism can be implemented in inflation, leading to suppressed tensor modes and addressing issues with previous models.

Findings

Clockwork mechanism can generate flat inflaton potentials.

Tensor modes are suppressed in clockwork inflation models.

Clockwork charge varies with site in de Sitter space.

Abstract

We investigate the recently proposed clockwork mechanism delivering light degrees of freedom with suppressed interactions and show, with various examples, that it can be efficiently implemented in inflationary scenarios to generate flat inflaton potentials and small density perturbations without fine-tunings. We also study the clockwork graviton in de Sitter and, interestingly, we find that the corresponding clockwork charge is site-dependent. As a consequence, the amount of tensor modes is generically suppressed with respect to the standard cases where the clockwork set-up is not adopted. This point can be made a virtue in resurrecting models of inflation which were supposed to be ruled out because of the excessive amount of tensor modes from inflation.