Equations of motion in gravity theories with nonminimal coupling: a loophole to detect torsion macroscopically?

TL;DR

This paper derives equations of motion in gravity theories with nonminimal coupling and torsion, highlighting potential for macroscopic detection of torsion effects through extended test bodies.

Contribution

It provides a systematic derivation of multipolar equations of motion for broad classes of nonminimal gravity theories with torsion, enabling experimental testing.

Findings

Certain nonminimal theories are sensitive to post-Riemannian structures.

Extended test bodies can detect torsion effects without microstructure.

Framework allows testing of entire classes of gravity theories.

Abstract

We derive multipolar equations of motion for gravitational theories with general nonminimal coupling in spacetimes admitting torsion. Our very general findings allow for the systematic testing of whole classes of theories by means of extended test bodies. One peculiar feature of certain subclasses of nonminimal theories turns out to be their sensitivity to post-Riemannian spacetime structures even in experiments without microstructured test matter.