2002/12/31 by Sergei M. Kopeikin · 2 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Pulsars and Gravitational Waves Research #Relativity and Gravitational Theory #astro-ph #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1016/s0375-9601(03)00613-3
published as Phys.Lett. A312 (2003) 147-157 · 15 pages, 2 figures, final version accepted to Phys. Lett. A
arxiv created 2003/03/28 · openalex publication_date 2003/05/13 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Gravitational physics of VLBI experiment conducted on September 8, 2002 and dedicated to measure the speed of gravity (a fundamental constant in the Einstein equations) is treated in the first post-Newtonian approximation. Explicit speed-of-gravity parameterization is introduced to the Einstein equations to single out the retardation effect caused by the finite speed of gravity in the relativistic time delay of light, passing through the variable gravitational field of the solar system. The speed-of-gravity 1.5 post-Newtonian correction to the Shapiro time delay is derived and compared with our previous result obtained by making use of the post-Minkowskian approximation. We confirm that the 1.5 post-Newtonian correction to the Shapiro delay depends on the speed of gravity cg that is a directly measurable parameter in the VLBI experiment.