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General Relativistic Theory of the VLBI Time Delay in the Gravitational Field of Moving BodiesThe general relativistic theory of the gravitational VLBI experiment conducted on September 8, 2002 by Fomalont and Kopeikin is explained. Equations of radio waves (light) propagating from the quasar to the observer are integrated in the time-dependent gravitational field of the solar system by making use of either retarded or advanced solutions of the Einstein field equations. This mathematical technique separates explicitly the effects associated with the propagation of gravity from those associated with light in the integral expression for the relativistic VLBI time delay of light. We prove that the relativistic correction to the Shapiro time delay, discovered by Kopeikin (ApJ, 556, L1, 2001), changes sign if one retains direction of the light propagation but replaces the retarded for the advanced solution of the Einstein equations. Hence, this correction is associated with the propagation of gravity. The VLBI observation measured its speed, and that the retarded solution is the correct one.
Document ID
20050186671
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
Authors
Kopeikin, Sergei
(Missouri Univ. Columbia, MO, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2003
Publication Information
Publication: Proceedings of the 2003 NASA/JPL Workshop on Fundamental Physics in Space
Subject Category
Astronomy
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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