A Coincidence Null Test for Poisson-Distributed Events

TL;DR

This paper introduces a universal null test for assessing the significance of coincident transient events across multiple sensors, particularly applied to gravitational-wave detectors like LIGO and Virgo.

Contribution

It presents a new statistical method for evaluating the independence of signals across sensors, aiding in the identification of genuine gravitational waves versus noise artifacts.

Findings

Successfully applied to simulated gravitational-wave events

Effectively distinguished real signals from noise in real data

Provided a tool for studying detector artifacts and their origins

Abstract

When transient events are observed with multiple sensors, it is often necessary to establish the significance of coincident events. We derive a universal null test for an arbitrary number of sensors motivated by the archetypal detection problem for independent Poisson-distributed events in gravitational-wave detectors such as LIGO and Virgo. In these detectors, transient events may be witnessed by myriad channels that record interferometric signals and the surrounding physical environment. We apply our null test to a broad set of simulated gravitational-wave events as well as to a real gravitational-wave detection to determine which auxiliary channels do and do not witness real gravitational waves, and therefore which are safe to use when constructing vetoes. We also describe how our approach can be used to study detector artifacts and their origin, as well as to quantify the statistical independence of candidate GW signals from noise artifacts observed in auxiliary channels.