Cosmological implications of a supersymmetric extension of the Brans-Dicke theory

TL;DR

This paper explores a supersymmetric extension of the Brans-Dicke theory, replacing the Planck mass with a superfield, revealing non-universal matter coupling and potential equivalence principle violations.

Contribution

It introduces a supersymmetric version of Brans-Dicke theory, analyzing its implications for dark matter, dark energy, and fundamental gravitational principles.

Findings

Gravitational sector does not couple universally to matter in the supersymmetric model.

Potential violations of the weak equivalence principle are identified.

The model suggests new links between supersymmetry, dark matter, and dark energy.

Abstract

In the Brans-Dicke theory the Planck mass is replaced by a dynamical scalar field. We consider here the supersymmetric analogous of this mechanism replacing in the supergravity Lagrangian the Planck mass with a chiral superfield. This analysis is motivated by the research of possible connections between supersymmetric Dark Matter scenarios and Dark Energy models based on Brans-Dicke-like theories. We find that, contrary to the original Brans-Dicke theory, in its supersymmetric analogous the gravitational sector does not couple to the matter sector in a universal metric way. As a result, violations of the weak equivalence principle could be present in such a scenario.