Compact binaries detection rates from gravitational wave interferometers: comparison of different procedures

TL;DR

This paper compares various approximation methods used to estimate gravitational wave detection rates of compact binary coalescences, highlighting biases introduced by these simplifications based on population and cosmic factors.

Contribution

It provides a detailed analysis of the impact of different approximation procedures on the accuracy of detection rate estimates for gravitational wave observatories.

Findings

Different approximation methods introduce biases in detection rate estimates.

Biases depend on the statistical properties of binary populations.

More accurate procedures reduce estimation biases.

Abstract

In this paper we perform a detailed analysis of the effect of various approximations which have been used in the literature to compute the detection rates of compact binary coalescences for interferometric gravitational wave detectors. We evaluate the detection rates for the coalescence of BH-BH, NS-NS, and BH-NS binaries taking into account their specific statistical properties obtained from population synthesis models, the cosmic star formation rate history, and the effects of redshift on the emitted gravitational wave signals. The results are compared with those obtained with procedures that are based on different levels of approximations, such as adopting averaged values for the total mass and symmetric mass ratio for all the systems of a binary population, using these to compute the horizon distance for individual detectors, or estimating the coalescence rate density within this distance by its local value. We show that these approximations introduce a bias which depends not only on the approximation which is used, but also on the statistical properties of the considered binary population.