Limits on Lorentz violation in gravity from worldwide superconducting gravimeters

TL;DR

This study used a global network of superconducting gravimeters and a first-principles tidal model to set new bounds on Lorentz violation in gravity, improving previous limits by an order of magnitude.

Contribution

It introduces a novel approach using first-principles tidal models with superconducting gravimeters to constrain Lorentz violation in gravity.

Findings

Bounded space-space components of gravitational Lorentz violation up to 10^{-10}

Improved constraints by an order of magnitude over previous atom-interferometer tests

Demonstrated the importance of accurate tidal modeling in Lorentz violation searches

Abstract

We investigated Lorentz violation through anisotropy of gravity using a worldwide array of 12 superconducting gravimeters. The Lorentz-violating signal is extracted from the difference between measured gravity and a tidal model. At the level of sensitivity we reach, ocean tides start to play an important role. However, most models available that include ocean tides are empirically based on measured gravity data, which may contain Lorentz-violating signal. In this work we used an ocean tides included tidal model derived from first principles to extract Lorentz-violating signal for the first time. We have bounded space-space components of gravitational Lorentz violation in the minimal standard model extension (SME) up to the order of $10^{-10}$, one order of magnitude improved relative to previous atom-interferometer tests.