Axion-dilaton-modulus gravity theory of Brans-Dicke-type and conformal symmetry

TL;DR

This paper explores conformal symmetry in an axion-dilaton-modulus gravity framework of Brans-Dicke type, emphasizing the importance of invariance under unit transformations and its implications for matter coupling and geometry.

Contribution

It distinguishes between general conformal symmetry and invariance under physical unit transformations, proposing non-minimal dilaton-matter coupling as a key feature.

Findings

Invariance under unit transformations constrains matter coupling.

Non-minimal dilaton coupling is favored for physical consistency.

Geometrical implications of conformal symmetry are discussed.

Abstract

Conformal symmetry is investigated within the context of axion-dilaton-modulus theory of gravity of Brans-Dicke-type. A distinction is made between general conformal symmetry and invariance under transformations of the physical units. The conformal degree of symmetry of the theory is studied when quantum fermion (lepton) modes with electromagnetic interaction are considered. Based on the requirement of invariance of the physical laws under general transformations of the units of measure, arguments are given that point at a matter action with non-minimal coupling of the dilaton to the matter fields as the most viable description of the world within the context of the model studied. The geometrical implications of the results obtained are discussed.