The Sagnac effect in superfluids

TL;DR

This paper discusses the interpretation of the Sagnac effect in superfluids, arguing that a general relativity-based explanation applies universally across various physical systems, including superfluids.

Contribution

It clarifies the interpretation of the Sagnac effect in superfluids, challenging recent review articles by emphasizing a unified general relativity explanation.

Findings

The Sagnac effect is observed in superfluids.

A general relativity explanation applies to all systems.

The paper challenges recent alternative interpretations.

Abstract

We comment on the interpretation of absolute rotation measurements with superfluids, which involve the Sagnac effect. This effect, first observed in rotating optical interferometers, has now been seen in a host of different physical systems, ranging from atomic clocks to electrons, neutrons, atomic beams, ... We show that the time-honored explanation of this effect based on general relativity provides a common explanation for all these systems, including superfluids, in contradistinction with the views expressed in a recent review article.