General Relativistic Effects in Atom Interferometry

TL;DR

This paper develops a relativistic framework for atom interferometry, enabling laboratory tests of general relativity with unprecedented precision, including potential detection of relativistic effects and validation of fundamental principles.

Contribution

It introduces a formalism for calculating relativistic phase shifts in atom interferometers, expanding their use in testing general relativity and related phenomena.

Findings

Proposes experiments to test the equivalence principle to 1 part in 10^15.

Estimates relativistic effects measurable in laboratory settings.

Suggests applications to various gravitational metrics and cosmological effects.

Abstract

Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the non-relativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. From this we develop a method for calculating the phase shift in general relativity. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity. The potentially testable relativistic effects include the non-linear three-graviton coupling, the gravity of kinetic energy, and the falling of light. We propose experiments, one currently under construction, that could provide a test of the principle of equivalence to 1 part in 10^15 (300 times better than the present limit), and general relativity at the 10% level, with many potential future improvements. We also consider applications to other metrics including the Lense-Thirring effect, the expansion of the universe, and preferred frame and location effects.