The Aharonov-Bohm Effect in Gravity

J. S. Dowker

Vu B Ho, Michael J Morgan

The gravitational Aharonov-Bohm (AB) effect is examined in the weak-field approximation to general relativity. In analogy with the electromagnetic AB effect, we find that a gravitoelectromagnetic 4-vector potential gives rise to interference effects. A matter wave interferometry experiment, based on a modification of the gravity-induced quantum interference experiment of Colella, Overhauser and Werner (COW), is proposed to explicitly test the gravitoelectric version of the AB effect in a uniform gravitational field.

J M Reed

A complete walkthrough of how the substrate framework explains both the classic electromagnetic Aharonov-Bohm effect (1959) and the recent gravitational Aharonov-Bohm experiment (Stanford 2022). This chapter draws on results from substrate quantum gravity (SQG, the framework for gravity from substrate) and the GUT extension (the framework for the Standard Model gauge structure including U(1)_X). Both effects emerge from the same underlying substrate physics — and that turns out to be a major conceptual win for the framework.

Vladimir D. Skarzhinsky

Donald H. Kobe

Gao, Shan

Testing whether gravity is quantum or classical remains a cornerstone challenge in fundamental physics. We introduce a practical tabletop experiment to probe gravity's quantum nature via the gravitational Aharonov-Bohm (AB) effect in atom interferometry. Our approach hinges on two pivotal insights: First, unlike electromagnetic AB effects where constant charge ensures gauge-invariant phases for closed paths, semiclassical gravity couples to the particle's total energy, rendering the AB phase gauge-dependent and unobservable when energies differ between paths due to environmental noise or controlled perturbations. Second, in quantum gravity—treating source, particle, and field as quantum—the total phase splits into a gauge-dependent particle contribution and a gauge-invariant source backreaction, yielding precisely half the nominal AB phase as observable. This halved phase discriminates quantum from classical gravity without requiring massive superpositions, aligning with existing technology. Remarkably, Overstreet et al.'s (Science 375, 226 (2022)) data already reveal a nonzero measured AB phase, providing the first experimental evidence for gravitational quantization.