Testing General Relativity with Atom Interferometry

The unprecedented precision of atom interferometry will soon lead to laboratory tests of general relativity to levels that will rival or exceed those reached by astrophysical observations. We propose such an experiment that will initially test the equivalence principle to 1 part in 10¹⁵ (300 times better than the current limit), and 1 part in 10¹⁷ in the future. It will also probe general relativistic effects—such as the nonlinear three-graviton coupling, the gravity of an atom’s kinetic energy, and the falling of light—to several decimals. In contrast with astrophysical observations, laboratory tests can isolate these effects via their different functional dependence on experimental variables.