Efficient gravitational-wave glitch identification from environmental data through machine learning

The LIGO observatories detect gravitational waves through monitoring changes in the detectors' length down to below ${10}^{\ensuremath{-}19}\text{ }\text{ }\mathrm{m}/\sqrt{\mathrm{Hz}}$ variations---a small fraction of the size of the atoms that make up the detector. To achieve this sensitivity, the detector and its environment need to be closely monitored. Beyond the gravitational-wave data stream, LIGO continuously records hundreds of thousands of channels of environmental and instrumental data in order to monitor for possibly minuscule variations that contribute to the detector noise. A particularly challenging issue is the appearance in the gravitational wave signal of brief, loud noise artifacts called ``glitches,'' which are environmental or instrumental in origin but can mimic true gravitational waves and therefore hinder sensitivity. Currently, they are primarily identified by analysis of the gravitational-wave data stream, and auxiliary data channels often provide corroborating evidence. Here we present a machine learning approach that can identify glitches by considering all environmental and detector data channels, a task that has not previously been pursued due to its scale and the number of degrees of freedom within gravitational-wave detectors. The presented method is capable of reducing the gravitational-wave detector network's false alarm rate and improving the LIGO instruments, consequently enhancing detection confidence.