Accurate effective-one-body waveforms of inspiralling and coalescing black-hole binaries

The effective-one-body (EOB) formalism contains several flexibility parameters, notably a(5), upsilon(pole) and (a) over bar (RR). We show here how to jointly constrain the values of these parameters by simultaneously best-fitting the EOB waveform to two, independent, numerical relativity (NR) simulations of inspiralling and/or coalescing binary black-hole systems: published Caltech-Cornell inspiral data (considered for gravitational wave frequencies Mw <= 0.1) on one side, and newly computed coalescence data on the other side. The resulting, approximately unique, "best-fit" EOB waveform is then shown to exhibit excellent agreement with NR coalescence data for several mass ratios. The dephasing between this best-fit EOB waveform and published Caltech-Cornell inspiral data is found to vary between -0.0014 and +0.0008 radians over a time span of similar to 2464M up to gravitational wave frequency Mw = 0.1, and between +0.0013 and -0.0185 over a time span of 96M after Mw = 0.1 up to Mw = 0. 1565. The dephasings between EOB and the new coalescence data are found to be smaller than: (i) +/- 0.025 radians over a time span of 730M (11 cycles) up to merger, in the equal-mass case,and (ii) +/- 0.05 radians over a time span of about 950M ( 17 cycles) up to merger in the 2:1 mass-ratio case. These new results corroborate the aptitude of the EOB formalism to provide accurate representations of general relativistic waveforms, which are needed by Currently operating gravitational wave detectors.