Faithful effective-one-body waveforms of equal-mass coalescing black-hole binaries

We compare a recently derived, resummed high post-Newtonian accuracy effective-one-body (EOB) quadrupolar waveform to the results of a numerical simulation of the inspiral and merger of an equal-mass black-hole binary. We find a remarkable agreement, both in phase and in amplitude, with a maximal dephasing which can be reduced below +/- 0.005 gravitational-wave cycles over 12 gravitational-wave cycles corresponding to the end of the inspiral, the plunge, the merger, and the beginning of the ring-down. This level of agreement is shown for two different values of the effective fourth post-Newtonian parameter a(5), and for corresponding, appropriately flexed values of the radiation-reaction resummation parameter v(pole). In addition, our resummed-EOB amplitude agrees to better than the 1% level with the numerical-relativity one up to the late inspiral. These results, together with other recent work on the EOB-numerical-relativity comparison, confirm the ability of the EOB formalism to accurately capture the general-relativistic waveforms.