A small non-vanishing cosmological constant from the Krein-Gupta-Bleuler vacuum

TL;DR

This paper explores how the Krein-Gupta-Bleuler vacuum could explain the small but non-zero cosmological constant, offering a covariant quantum gravity framework in de Sitter space.

Contribution

It proposes a novel connection between the KGB vacuum and the cosmological constant, advancing a covariant quantum gravity approach in de Sitter spacetime.

Findings

KGB vacuum may account for the small cosmological constant

Provides a covariant quantum gravity formulation in de Sitter space

Suggests a pathway to determine the cosmological constant value

Abstract

We point out a potential relevance between the Krein-Gupta-Bleuler (KGB) vacuum leading to a fully covariant quantum field theory for gravity in de Sitter (dS) spacetime and the observable smallness of the cosmological constant. This may provide a formulation of linear quantum gravity in a framework amenable to developing a more complete theory determining the value of the cosmological constant.