Improved binary black hole search discriminator from the singular value decomposition of non-Gaussian noise transients

Abstract The sensitivity of current gravitational wave (GW) detectors to transient GW signals is severely affected by a variety of non-Gaussian and non-stationary noise transients, such as the blip, tomte, koi fish, and low-frequency blip ‘glitches’. These glitches share some time–frequency resemblance with GW signals from binary black holes. In earlier works (Joshi 2021 Phys. Rev. D 103 044035), (Choudhary 2024 et al Phys. Rev. D 110 044051), the authors presented a method for constructing a χ 2 -distributed optimized statistic, based on the unified formalism of χ 2 discriminators (Dhurandhar 2017 Phys. Rev. D 96 103018), to distinguish the blip glitches from the compact binary coalescence signals. Unlike past works, the new χ 2 discriminator is constructed from the most significant singular vectors obtained from the singular value decomposition of different classes of glitches in real detector data. We find that the chi-square developed in this work performs as efficiently as in (Choudhary 2024 et al Phys. Rev. D 110 044051), which used sine-Gaussian basis vectors. This result supports past empirical findings that these glitches are reasonably well-modeled by sine-Gaussians. It also introduces a method for constructing signal- and glitch-based χ 2 discriminators by directly using real data containing the glitches and, thus, holds promise for extensions to glitches that are captured less well by sine-Gaussians or other analytical functions.