Improving the background estimation technique in the GstLAL inspiral pipeline with the time-reversed template bank

TL;DR

This paper introduces a novel background estimation method for gravitational-wave searches that uses time-reversed waveforms to prevent signal contamination, improving robustness as detection rates increase.

Contribution

The paper presents a new background estimation technique using time-reversed templates to reduce signal leakage in gravitational-wave data analysis.

Findings

Effectively avoids signal contamination at ~1 event per 20 seconds

Maintains a clean background model even with frequent signals

Enhances the reliability of gravitational-wave event significance estimation

Abstract

Background estimation is important for determining the statistical significance of a gravitational-wave event. Currently, the background model is constructed numerically from the strain data using estimation techniques that insulate the strain data from any potential signals. However, as the observation of gravitational-wave signals become frequent, the effectiveness of such insulation will decrease. Contamination occurs when signals leak into the background model. In this work, we demonstrate an improved background estimation technique for the searches of gravitational waves (GWs) from binary neutron star coalescences by time-reversing the modeled GW waveforms. We found that the new method can robustly avoid signal contamination at a signal rate of about one per 20 seconds and retain a clean background model in the presence of signals.