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arXiv · 1606.09139

Post-Newtonian celestial mechanics in scalar-tensor cosmology

Andrei Galiautdinov·Sergei M. Kopeikin
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Abstract

Applying the recently developed dynamical perturbation formalism on cosmological background to scalar-tensor theory, we provide a solid theoretical basis and a rigorous justification for phenomenological models of orbital dynamics that are currently used to interpret experimental measurements of the time-dependent gravitational constant. We derive the field equations for the scalar-tensor perturbations and study their gauge freedom associated with the cosmological expansion. We find a new gauge eliminating a prohibitive number of gauge modes in the field equations and significantly simplifying post-Newtonian equations of motion for localized astronomical systems in the universe with time-dependent gravitational constant. We identify several new post-Newtonian terms and calculate their effect on secular cosmological evolution of the osculating orbital elements.

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Andrei Galiautdinov, Sergei M. Kopeikin. 2016-06-29. Post-Newtonian celestial mechanics in scalar-tensor cosmology. https://doi.org/10.1103/physrevd.94.044015

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