The Confrontation between General Relativity and Experiment

TL;DR

This paper reviews experimental tests of general relativity, confirming many of its predictions with high precision, and discusses future experiments that could reveal new physics from unification or quantum gravity theories.

Contribution

It provides a comprehensive overview of the current experimental status of general relativity and discusses future tests for potential new interactions.

Findings

EEP well supported by experiments

High-precision tests of post-Newtonian effects

Gravitational-wave damping matches predictions

Abstract

The status of experimental tests of general relativity and of theoretical frameworks for analysing them is reviewed. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eotvos experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational-wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and other binary pulsar systems have yielded other tests, especially of strong-field effects. When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.