A template bank for gravitational waveforms from coalescing binary black holes: non-spinning binaries

TL;DR

This paper introduces a comprehensive template bank for detecting gravitational waves from non-spinning binary black hole coalescences, modeling all three stages— inspiral, merger, and ring-down— to improve detection sensitivity and parameter estimation.

Contribution

It presents a novel two-dimensional family of templates that coherently model all coalescence stages and offers a method to construct interpolated template banks from numerical relativity waveforms.

Findings

Enhanced detection sensitivity across a broad mass range.

Significant improvement over previous stage-specific searches.

Potential increase in ground-based interferometer event rates.

Abstract

Gravitational waveforms from the inspiral and ring-down stages of the binary black hole coalescences can be modelled accurately by approximation/perturbation techniques in general relativity. Recent progress in numerical relativity has enabled us to model also the non-perturbative merger phase of the binary black-hole coalescence problem. This enables us to \emph{coherently} search for all three stages of the coalescence of non-spinning binary black holes using a single template bank. Taking our motivation from these results, we propose a family of template waveforms which can model the inspiral, merger, and ring-down stages of the coalescence of non-spinning binary black holes that follow quasi-circular inspiral. This two-dimensional template family is explicitly parametrized by the physical parameters of the binary. We show that the template family is not only \emph{effectual} in detecting the signals from black hole coalescences, but also \emph{faithful} in estimating the parameters of the binary. We compare the sensitivity of a search (in the context of different ground-based interferometers) using all three stages of the black hole coalescence with other template-based searches which look for individual stages separately. We find that the proposed search is significantly more sensitive than other template-based searches for a substantial mass-range, potentially bringing about remarkable improvement in the event-rate of ground-based interferometers. As part of this work, we also prescribe a general procedure to construct interpolated template banks using non-spinning black hole waveforms produced by numerical relativity.