Validating the effective-one-body model of spinning, precessing binary black holes against numerical relativity

TL;DR

This paper validates the effective-one-body (EOB) model for precessing binary black holes by comparing it to 70 numerical relativity waveforms, demonstrating high accuracy within 3% unfaithfulness for a wide parameter range.

Contribution

It provides the first extensive comparison of precessing EOBNR waveforms to a large set of NR simulations, including new prescriptions for the ringdown signal without recalibration.

Findings

EOBNR waveforms have unfaithfulness within 3% of NR waveforms.

The comparison covers mass ratios 1-5 and spins up to 0.5.

Results hold for total masses 10-200 solar masses.

Abstract

In Ref. [1], the properties of the first gravitational wave detected by LIGO, GW150914, were measured by employing an effective-one-body (EOB) model of precessing binary black holes whose underlying dynamics and waveforms were calibrated to numerical-relativity (NR) simulations. Here, we perform the first extensive comparison of such EOBNR model to 70 precessing NR waveforms that span mass ratios from 1 to 5, dimensionless spin magnitudes up to 0.5, generic spin orientations, and length of about 20 orbits. We work in the observer's inertial frame and include all $\ell=2$ modes in the gravitational-wave polarizations. We introduce new prescriptions for the EOB ringdown signal concerning its spectrum and time of onset. For total masses between 10Msun and 200Msun, we find that precessing EOBNR waveforms have unfaithfulness within about 3% to NR waveforms when considering the Advanced-LIGO design noise curve. This result is obtained without recalibration of the inspiral-plunge of the underlying nonprecessing EOBNR model. The unfaithfulness is computed with maximization over time and phase of arrival, sky location and polarization of the EOBNR waveform and it is averaged over sky location and polarization of the NR signal. We also present comparisons between NR and EOBNR waveforms in a frame that tracks the orbital precession.