Fake signals caused by heavy mass motions near a sensitive spherical gravitational wave antenna

TL;DR

This study quantitatively analyzes how heavy mass motions near spherical gravitational wave detectors can produce fake signals, identifying characteristic frequencies and showing these false signals are generally below the detector's sensitivity in realistic scenarios.

Contribution

It provides a detailed analysis of mass motion effects on spherical GW detectors, highlighting the frequency dependence and magnitude of fake signals, which was not thoroughly characterized before.

Findings

Fake signals have characteristic frequencies related to external mass motion.

In realistic conditions, fake signals are well below the detector's sensitivity.

The effect of heavy mass motions can be quantitatively predicted and distinguished from real signals.

Abstract

This paper analyses in quantitative detail the effect caused by a moving mass on a spherical gravitational wave detector. This applies to situations where heavy traffic or similar disturbances happen near the GW antenna. Such disturbances result in quadrupole tidal stresses in the antenna mass, and they therefore precisely fake a real gravitational signal. The study shows that there always are characteristic frequencies, depending on the motion of the external masses, at which the fake signals are most intense. It however appears that, even at those frequencies, fake signals should be orders of magnitude below the sensitivity curve of an optimised detector, in likely realistic situations.