Equivalence principle in scalar-tensor gravity

TL;DR

This paper confirms the validity of the equivalence principle for unstructured test bodies within scalar-tensor gravity theories, using a covariant approach to derive equations of motion and facilitate experimental tests.

Contribution

It provides a direct, covariant confirmation of the equivalence principle in scalar-tensor gravity, applicable to a broad class of theories and test bodies.

Findings

Equivalence principle holds for unstructured test bodies in scalar-tensor gravity.

A covariant method for deriving equations of motion is developed.

Supports experimental testing of scalar-tensor theories.

Abstract

We present a direct confirmation of the validity of the equivalence principle for unstructured test bodies in scalar tensor gravity. Our analysis is complementary to previous approaches and valid for a large class of scalar-tensor theories of gravitation. A covariant approach is used to derive the equations of motion in a systematic way and allows for the experimental test of scalar-tensor theories by means of extended test bodies.