Multi-detector null-stream-based $\chi^2$ statistic for compact binary coalescence searches

Understand

We develop a new multi-detector signal-based discriminator to improve the sensitivity of searches for gravitational waves from compact binary coalescences.

• The new statistic is the traditional $\chi^2$ computed on a null-stream synthesized from the gravitational-wave detector strain time-series of three detectors.
• This null-stream-$\chi^2$ statistic can be extended to networks involving more than three detectors as well.
• The null-stream itself was proposed as a discriminator between correlated unmodeled signals in multiple detectors, such as arising from a common astrophysical source, and uncorrelated noise transients.