On the Detection of Scalar Field Induced Spacetime Torsion

TL;DR

This paper explores how scalar field-induced torsion in spacetime could alter gravitational predictions, suggesting that traditional geodesic-based methods might need revision in scalar-tensor gravity theories like Brans-Dicke.

Contribution

It reformulates Brans-Dicke theory with a torsionful connection and calculates the perihelion shift of Mercury under this new hypothesis, highlighting potential observational differences.

Findings

Perihelion shift calculations differ from standard predictions.

Significant scalar field coupling could affect planetary orbits.

Current timekeeping methods may require refinement in this context.

Abstract

We argue that the geodesic hypothesis based on the autoparalllels of the Levi-Civita connection may need refinement in the scalar- tensor theories of gravity. Based on a reformulation of the Brans- Dicke theory in terms of a connection with torsion determined dynamically in terms of the gradient of the Brans-Dicke scalar field, we compute the perihelion shift in the orbit of Mercury on the alternative hypothesis that its worldline is an autoparallel of a connection with torsion. If the Brans-Dicke scalar field couples significantly to matter and test particles move on such worldlines, the current time keeping methods based on the conventional geodesic hypothesis may need refinement.