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  • Print publication year: 2018
  • Online publication date: September 2018

6 - Equations of Motion in the PPN Formalism


We derive the equations of motion for a variety of physical systems in the PPN formalism, including photons, fluid systems, and N-body systems consisting of well-separated self-gravitating objects. We also specialize to two-body systems and describe the framework for calculating perturbations of Keplerian orbit elements induced by post-Newtonian corrections in the equations of motion. For a class of theories based on an invariant action, we obtain the Lagrangian that describes the dynamics of an N-body system. We derive the locally-measured, or effective gravitational constant, as measured by a Cavendish experiment, within the PPN formalism. For spinning bodies, we obtain the equations of motion and the equations of spin precession.

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Theory and Experiment in Gravitational Physics
  • Online ISBN: 9781316338612
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