The effects of Chern-Simons gravity on bodies orbiting the Earth

TL;DR

This paper explores how Chern-Simons gravity, a theoretical extension of general relativity inspired by string theory, affects the orbits and gyroscopic precession around Earth, providing new experimental constraints.

Contribution

It derives the linearized spacetime solution for Chern-Simons gravity around a spinning mass and calculates its effects on satellite orbits and gyroscope precession.

Findings

New modifications to gravitomagnetic fields identified

Derived constraints on Chern-Simons parameters from satellite data

Enhanced understanding of parity-violating gravitational interactions

Abstract

One of the possible low-energy consequences of string theory is the addition of a Chern-Simons term to the standard Einstein-Hilbert action of general relativity. It can be argued that the quintessence field should couple to this Chern-Simons term, and if so, it drives in the linearized theory a parity-violating interaction between the gravito-electric and gravitomagnetic fields. In this paper, the linearized spacetime for Chern-Simons gravity around a massive spinning body is found to include new modifications to the gravitomagnetic field that have not appeared in previous work. The orbits of test bodies and the precession of gyroscopes in this spacetime are calculated, leading to new constraints on the Chern-Simons parameter space due to current satellite experiments.