Gravitational Faraday Holonomy

TL;DR

This paper investigates how engineered closed optical paths in Kerr spacetime exhibit significant gravitational Faraday holonomy, which can be amplified by trajectory design, offering potential for experimental measurement of gravitational effects.

Contribution

It introduces a method to generate large gravitational Faraday holonomy through specific non-equatorial trajectories in Kerr spacetime, highlighting the role of path asymmetry and proximity to the ergosphere.

Findings

Large gravitational Faraday holonomy achievable with engineered trajectories.

Holonomy increases with proximity to the ergosphere.

Trajectories passing through the equatorial plane at radial turning points are key.

Abstract

Closed optical trajectories in Kerr spacetime are engineered to exhibit a marked lack of symmetry. The eccentricity manifests as a holonomy in gravitational Faraday rotation that can be made arbitrarily large by radial translation of the common location of source and receiver. All trajectories are non-equatorial and include a passage through the equatorial plane at the radial turning point, where the trajectory and pseudo-magnetic field are well-aligned. This, combined with path asymmetry, results in a large gravitational Faraday holonomy that lends itself to experimental measurement. Trajectories that start further away from the singularity pass more closely to the ergosphere, thus transiting a more distorted region of spacetime with concomitant amplification of gravitational Coriolis force.