Sagnac Effect, Ring Lasers and Terrestrial Tests of Gravity

TL;DR

This paper reviews the theoretical basis of the Sagnac Effect and discusses how ring laser experiments like GINGER can measure relativistic gravitational effects on Earth, potentially testing alternative gravity theories.

Contribution

It provides a comprehensive analysis of the Sagnac Effect in terrestrial settings and details the GINGER experimental setup for measuring post-Newtonian gravity effects.

Findings

Theoretical foundations of the Sagnac Effect are established.

Terrestrial measurements can constrain alternative gravity theories.

The GINGER experiment setup is described in detail.

Abstract

Light can be used as a probe to explore the structure of space-time: this is usual in astrophysical and cosmological tests, however it has been recently suggested that this can be done also in terrestrial laboratories. Namely, the GINGER project aims at measuring post-Newtonian effects, such as the gravito-magnetic ones, in an Earth based laboratory, by means of a ring lasers array. Here, we first review the theoretical foundations of the Sagnac Effect, on which ring lasers are based, and then we study the Sagnac Effect in a terrestrial laboratory, emphasizing the origin of the gravitational contributions that GINGER aims at measuring. Moreover, we show that accurate measurements allow to set constraints on theories of gravity different from General Relativity. Eventually, we describe the experimental setup of GINGER.