Toward faithful templates for non-spinning binary black holes using the effective-one-body approach

TL;DR

This paper develops an improved effective-one-body model for non-spinning binary black hole mergers, achieving high accuracy in waveform predictions by calibrating with numerical relativity simulations, useful for gravitational wave detection and analysis.

Contribution

The authors extend the EOB model with a 4PN correction and calibrate it against numerical relativity waveforms for various mass ratios, enhancing its accuracy during merger and ringdown phases.

Findings

Phase difference < 8% of a cycle at ringdown

Effective EOB waveform matches numerical relativity within specified accuracy

Applicable for gravitational wave detection and parameter estimation

Abstract

We present an accurate approximation of the full gravitational radiation waveforms generated in the merger of non-eccentric systems of two non-spinning black holes. Utilizing information from recent numerical relativity simulations and the natural flexibility of the effective-one-body (EOB) model, we extend the latter so that it can successfully match the numerical relativity waveforms during the last stages of inspiral, merger and ringdown. By ``successfully'' here, we mean with phase differences < 8% of a gravitational-wave cycle accumulated by the end of the ringdown phase, maximizing only over time of arrival and initial phase. We obtain this result by simply adding a 4-post-Newtonian order correction in the EOB radial potential and determining the (constant) coefficient by imposing high-matching performances with numerical waveforms of mass ratios m1/m2 = 1, 3/2, 2 and 4, m1 and m2 being the individual black-hole masses. The final black-hole mass and spin predicted by the numerical simulations are used to determine the ringdown frequency and decay time of three quasi-normal-mode damped sinusoids that are attached to the EOB inspiral-(plunge) waveform at the EOB light-ring. The EOB waveforms might be tested and further improved in the future by comparison with extremely long and accurate inspiral numerical-relativity waveforms. They may already be employed for coherent searches and parameter estimation of gravitational waves emitted by non-spinning coalescing binary black holes with ground-based laser-interferometer detectors.