Maximally symmetric spaces in Brans-Dicke theory and the cosmological constant

TL;DR

This paper explores a toy model in Brans-Dicke theory where the cosmological constant emerges from symmetry properties of the vacuum, highlighting an alternative conceptual approach despite unrealistic parameter values.

Contribution

It introduces a model linking the cosmological constant to symmetry properties in a scalar-tensor gravity framework, offering a novel perspective on its origin.

Findings

Shows the cosmological constant can be associated with vacuum symmetry

Demonstrates an alternative way for the cosmological constant to arise

Highlights limitations due to parameter values

Abstract

In this note we discuss a toy model in which the value of the effective cosmological constant is associated with a symmetry properties of the vacuum background solution and defined by the model parameter associated with a scalar field non-minimally coupled to gravity. Although the parameters in the model seem to have unrealistic values to account for the present value of the cosmological constant, the model demonstrates a possible alternative way it can arise.