Locally optimum network detectors of unmodeled gravitational wave bursts in glitch noise

Abstract

The detection of unmodeled gravitational wave transients (bursts) using a network of interferometric detectors affected by non-Gaussian (glitchy) noise is studied, starting from first principles, for the simplest case where the source position on the celestial sphere is fiducially known from different (e.g., optical, radio, or neutrino) observations. Interferometer noise modelling is preliminarily discussed in an operational perspective. Two alternative, locally optimum detectors are proposed and evaluated in simulated realistic non-Gaussian (glitchy) noise, together with robust implementations which are tolerant against incomplete knowledge or fluctuations of the noise features. These detectors outperform those based on the unrealistic stationary/Gaussian noise assumption, and in principle, do not require preliminary ad hoc data vetoing or laundering. They are structurally akin to those adopted in current data analysis pipelines, preserving their correlation structure, and use simple memoryless nonlinearities for data preprocessing, with only a minor added computational burden.