Solar-system tests of the relativistic gravity

Abstract

In 1859, Le Verrier discovered the Mercury perihelion advance anomaly. This anomaly turned out to be the first relativistic-gravity effect observed. During the 157 years to 2016, the precisions and accuracies of laboratory and space experiments, and of astrophysical and cosmological observations on relativistic gravity have been improved by 3-4 orders of magnitude. The improvements have been mainly from optical observations at first followed by radio observations. The achievements for the past 50 years are from radio Doppler tracking and radio ranging together with lunar laser ranging. At the present, the radio observations and lunar laser ranging experiments are similar in the accuracy of testing relativistic gravity. We review and summarize the present status of solar-system tests of relativistic gravity. With planetary laser ranging, spacecraft laser ranging and interferometric laser ranging (laser Doppler ranging) together with the development of drag-free technology, the optical observations will improve the accuracies by another 3-4 orders of magnitude in both the equivalence principle tests and solar-system dynamics tests of relativistic gravity. Clock tests and atomic interferometry tests of relativistic gravity will reach an ever-increasing precision. These will give crucial clues in both experimental and theoretical aspects of gravity, and may lead to answers to some profound issues in gravity and cosmology.

The energy dependence of micro black hole horizon in quantum gravity theory

“…The light travel time delay named Shapiro delay, which was firstly introduced by Shapiro [4], can also be used to test GR. The new measurements are consistent with the prediction of GR very well [5,6].…”

Atom interferometers and a small-scale test of general relativity

“…Similarly to gravitational waves, the effect is relatively weak and requires very precise apparatus to be observed. Numerous measurements of the effect have been made up to date, both in [22][23][24] and outside of the solar system [25]. In particular, gravity probe B launched in 2004 was able to measure the frame-dragging drift rate of −37.2 ± 7.2 mas/year, in good agreement with the theoretical prediction of −39.2 mas/year [26].…”

Stratified scalar field theories of gravitation with self-energy term and effective particle Lagrangian

“…The theories predict specific values for the classical gravitational tests, see in addition [53][54][55][56][57]. To compare the different theories in these tests, it should then be enough to compare just a few specific parameters of the field equation and of the particle Lagrangian of each theory.…”