Very Light Cosmological Scalar Fields from a Tiny Cosmological Constant

TL;DR

This paper proposes a mechanism where a scalar field's tiny mass, generated by the cosmological constant and protected by conformal symmetry, could influence current cosmological and particle physics parameters.

Contribution

It introduces a novel way to generate a small scalar field mass linked to the cosmological constant, with potential implications for fundamental constants.

Findings

Scalar field mass is comparable to the Hubble scale today

The mechanism links the scalar mass to the cosmological constant

Potential impact on variation of standard model parameters

Abstract

We discuss a mechanism which generates a mass term for a scalar field in an expanding universe. The mass of this field turns out to be generated by the cosmological constant and can be naturally small if protected by a conformal symmetry which is however broken in the gravitational sector. The mass is comparable today to the Hubble time. This scalar field could thus impact our universe today and for example be at the origin of a time variation of the couplings and masses of the parameters of the standard model.