Performance comparison of multi-detector detection statistics in targeted compact binary coalescence GW search

TL;DR

This paper compares multi-detector detection statistics for gravitational wave searches from compact binary coalescences, finding that a hybrid likelihood ratio statistic performs as well or better than Bayesian methods.

Contribution

It introduces an analytical Bayesian statistic for targeted CBC searches and compares its performance with existing maximum likelihood ratio methods.

Findings

Hybrid statistic performs as well or better than Bayesian methods

Analytical expression derived for Bayesian statistic using synthetic data streams

Simulations validate the effectiveness of the hybrid detection approach

Abstract

Global network of advanced Interferometric gravitational wave (GW) detectors are expected to be on-line soon. Coherent observation of GW from a distant compact binary coalescence (CBC) with a network of interferometers located in different continents give crucial information about the source such as source location and polarization information. In this paper we compare different multi-detector network detection statistics for CBC search. In maximum likelihood ratio (MLR) based detection approaches, the likelihood ratio is optimized to obtain the best model parameters and the best likelihood ratio value is used as statistic to make decision on the presence of signal. However, an alternative Bayesian approach involves marginalization of the likelihood ratio over the parameters to obtain the average likelihood ratio. We obtain an analytical expression for the Bayesian statistic using the two effective synthetic data streams for targeted search of non-spinning compact binary systems with an uninformative prior on the parameters. Simulations are carried out for testing the validity of the approximation and comparing the detection performance with the maximum likelihood ratio based statistics. We observe that the MLR {\it hybrid} statistic gives comparable or better performance with respect to the Bayesian statistic.