Light propagation and atom interferometry in gravity and dilaton fields

TL;DR

This paper models how dilaton fields, representing dark matter or equivalence principle violations, affect light propagation and atom interferometry signals, revealing that matter coupling dominates the phase shifts while electromagnetic effects are negligible.

Contribution

It introduces a framework for understanding light propagation in the presence of dilaton fields and analyzes their impact on atom interferometry experiments for gravity and dark matter detection.

Findings

Dilaton fields modify light's momentum transfer and finite speed effects in interferometers.

Electromagnetic contributions to phase are unaffected by dilaton fields.

Different atom-interferometric setups show measurable effects from dilaton-induced light propagation changes.

Abstract

Dark matter or violations of the Einstein equivalence principle influence the motion of atoms, their internal states as well as electromagnetic fields, thus causing a signature in the signal of atomic detectors. To model such new physics, we introduce dilaton fields and study the modified propagation of light used to manipulate atoms in light-pulse atom interferometers. Their interference signal is dominated by the matter's coupling to gravity and the dilaton. Even though the electromagnetic field contributes to the phase, no additional dilaton-dependent effect can be observed. However, the light's propagation in gravity enters via a modified momentum transfer and its finite speed. For illustration, we discuss effects from light propagation and the dilaton on different atom-interferometric setups, including gradiometers, equivalence principle tests, and dark matter detection.