Flat-space picture of gravity vs. General Relativity: a precision test for present ether-drift experiments

TL;DR

This paper re-analyzes data from modern ether-drift experiments to test a flat-space gravity model, finding evidence that supports the flat-space scenario over General Relativity.

Contribution

It provides a novel analysis of experimental data suggesting possible support for a flat-space gravity model, contrasting with standard General Relativity predictions.

Findings

Evidence supporting flat-space gravity scenario

Detection of anisotropy in light speed on Earth

Re-analysis reduces systematic effects concerns

Abstract

Modern ether-drift experiments in vacuum could in principle detect the tiny refractive index that, in a flat-space picture of gravity, is appropriate for an apparatus placed on the Earth's surface. In this picture, in fact, if there were a preferred reference frame, light on the Earth would exhibit a slight anisotropy with definite quantitative differences from General Relativity. By re-analyzing the data published by two modern experiments with rotating optical resonators, and concentrating on the part of the signal that should be free of spurious systematic effects, we have found evidences that would support the flat-space scenario.