Leveraging cross-detector parameter consistency measures to enhance sensitivities of gravitational-wave searches

All-sky searches for generic short-duration astrophysical gravitational-wave (GW) signals are often challenging because of noise transients. Developing novel signal-noise discriminators is crucial for GW transient searches with LIGO, Virgo, and KAGRA detectors. In this work, we demonstrate the sensitivity improvement of a weakly modeled GW transient search by leveraging the recently developed Jensen-Shannon divergence (JSD)-based cross-detector parameter consistency measure. We first extend a two-detector JSD-based measure developed in an earlier work [Ghosh et al., Phys. Rev. D 109, 064015 (2024)] to a three-detector network. We leverage this to modify the test statistic of the existing coherent WaveBurst (cWB)–Gaussian mixture modeling (GMM) algorithm for short-duration transients toward improving the search sensitivity to ad hoc waveforms like sine Gaussians, Gaussian pulses, and white noise bursts. We find that with the new method, which we term cWB-GMM-JSD, the sensitivity to the ad hoc waveforms, given by ℎrss⁢50 (the signal amplitude at which 50% of the injected signals can be detected), improves by ∼10%–20% at an inverse false alarm rate (IFAR) of 10 yr for the two-detector network consisting of the LIGO-Hanford (LHO) and LIGO-Livingston (LLO) detectors, and by ∼5%–10% at the same IFAR for the three-detector network consisting of the LHO, LLO, and Virgo detectors. Finally, we apply the modified statistic in the revised data analysis pipeline on the publicly available data from the third observing run (O3) of the LIGO and Virgo detectors. Although we do not find any new event in the O3 data, we see a notable rise in the statistical significance of most of the known GW events, which further testifies to the enhancement in sensitivity.