Prospects of detecting spacetime torsion

TL;DR

This paper develops a theoretical framework for detecting spacetime torsion by analyzing the motion of extended test bodies in various gravitational theories, highlighting potential experimental sensitivities even with ordinary matter.

Contribution

It provides multipolar equations of motion for general gravitational theories with torsion and nonminimal coupling, enabling systematic testing of these theories.

Findings

Extended test bodies can detect spacetime torsion.

Nonminimal coupling theories may be sensitive to torsion with ordinary matter.

Framework facilitates experimental testing of gravitational theories with torsion.

Abstract

How to detect spacetime torsion? In this essay we provide the theoretical basis for an answer to this question. Multipolar equations of motion for a very general class of gravitational theories with nonminimal coupling in spacetimes admitting torsion are given. Our findings provide a framework for the systematic testing of whole classes of theories with the help of extended test bodies. One surprising feature of nonminimal theories turns out to be their potential sensitivity to torsion of spacetime even in experiments with ordinary (not microstructured) test matter.