Thomas precession in post-Newtonian gravitoelectromagnetism

The well-known Thomas precession effect is discussed in the context of the post-Newtonian approximation to general relativity using the language of gravitoelectromagnetism (3-plus-1 splitting of gravitational theory). Preliminary discussion anchors the post-Newtonian coordinate system and choice of gravitational variables in the mathematical structure of fully nonlinear general relativity, linking the post-Newtonian gravitoelectric and gravitomagnetic fields to kinematical properties of the associated observer congruence. The transformation laws for these fields under a change of post-Newtonian coordinate system are derived first within the post-Newtonian theory and then by taking the limit of their fully nonlinear form to reveal the interpretation of the various terms in the post-Newtonian case. These transformation laws are then used to make a case for the existence of a gravitational analogue of the ordinary Thomas precession of the spin of a gyroscope.