Effect of Hubble parameter on the orbit of light ray and radar echo delay in Robertson-McVittie spacetime
哈勃参数对Robertson-McVittie时空中光线轨道的影响和雷达回波延迟修正

In this paper, the effect of Hubble parameter on the propagation of electromagnetic wave in Robertson-McVittie spacetime is discussed by using the post-Newtonian approximation method. To the bending test of light ray, the deflection angle caused by Hubble parameter H0 is calculated to its maximum amendatory term. Besides, the effects of finite distances of light source and receiver (d1 and d2 ) on deflection angle are also considered in this work. To the radar echo delay test, the maximum amendatory term to the formulae, induced by Hubble parameter, is given. The paper focuss on the study of influence of cosmological expansion on the propagation of electromagnetic wave. The work can be checked in the current high-precision gravity experiments in space and provides a theoretical basis for these experiments.