Conformal Higgs Inflation

TL;DR

This paper explores a Weyl-invariant theory linking gravity and the standard model, revealing unique gauge-inflaton couplings and discussing its potential to explain BICEP2 results, though with significant challenges.

Contribution

It introduces a scale-invariant framework unifying gravity and the standard model with novel gauge-inflaton interactions and examines its implications for inflationary observations.

Findings

Coupling between gauge field and inflaton in large field limit.

Standard model coupled to gravity in small field limit.

Difficulty in explaining BICEP2 results within this framework.

Abstract

We investigate a locally scale-invariant (that is, Weyl-invariant) theory which describes the coupling of gravity and the standard model from the viewpont of the Higgs mechanism and inflation. It is shown that this theory exhibits a peculiar feature of a coupling between the gauge field and the inflaton in a large field limit whereas it nicely describes the standard model coupled to general relativity in a small field limit. Moreover, we discuss a possibility that this Weyl invariant theory could explain the recent BICEP2 measurement by deforming the potential term in an appropriate way, and find it to be difficult to do that even if we introduce a non-analytical type of the potential.