Light deflection in the second post-Newtonian approximation of scalar-tensor theory of gravity

Abstract

In this paper, we use the metric coefficients and the equation of motion in the 2nd post-Newtonian approximation in scalar-tensor theory including intermediate range gravity to derive the deflection of light and compare it with previous works. These results will be useful for precision astrometry missions like GAIA (Global Astrometric Interferometer of Astrophysics), SIMS (The Space Interferometry Mission) and LATOR (Laser Astrometric Test Of Relativity) which aim at astrometry with microarcsecond and nanoarcsecond accuracies and need 2nd post-Newtonian framework and ephemeris to determine the stellar and spacecraft positions.