Consequences of Propagating Torsion in Connection-Dynamic Theories of Gravity

TL;DR

This paper investigates how torsion in connection-dynamic gravity theories could produce observable effects, but finds that in many models torsion decays rapidly, making detection unlikely with current experiments.

Contribution

It analyzes observational constraints on torsion modes in connection-dynamic gravity theories, focusing on the scalar torsion and its decay properties.

Findings

Torsion interacts with matter mainly as a massive scalar or spin-1 boson.

In many models, torsion decays quickly, avoiding detection.

No long-range torsion fields are expected in typical scenarios.

Abstract

We discuss the possibility of constraining theories of gravity in which the connection is a fundamental variable by searching for observational consequences of the torsion degrees of freedom. In a wide class of models, the only modes of the torsion tensor which interact with matter are either a massive scalar or a massive spin-1 boson. Focusing on the scalar version, we study constraints on the two-dimensional parameter space characterizing the theory. For reasonable choices of these parameters the torsion decays quickly into matter fields, and no long-range fields are generated which could be discovered by ground-based or astrophysical experiments.