Prospects for Measuring the Post-Newtonian \(\boldsymbol{\gamma}\) Parameter Using Two Satellites Equipped with Highly Stable Atomic Clocks

Abstract

We investigate the possibility of experimentally determining the value of the PPN \(\gamma\) parameter, which characterizes possible deviations from general relativity, by measuring the gravitational frequency shift of signals exchanged by two satellites in geo- and heliocentric orbits. We demonstrate that with modern optical clocks the accuracy of an experiment based on our concept can reach an accuracy of at least \(1.4\times 10^{-8}\), which is 3 orders of magnitude better than the current best result achieved with the Cassini interplanetary probe.