SESZIONE DI TORINO
I will discuss recent comparisons between Effective-One-Body (EOB), analytic gravitational waveforms for binary black hole coalescence and numerical relativity (NR) data from different groups: (published) Caltech-Cornell (inspiral) data, AEI and Jena (coalescence data. The EOB waveform contains several "flexibility parameters" that need to be fixed. I will show how to jointly determine the values of these parameters by simultaneously best-fitting the EOB waveform to numercal relativity waveforms. The resulting, essentially unique, ``best-fit'' EOB waveform is then shown to exhibit excellent agreement with NR coalescence data for several mass ratios. The dephasing between EOB￿ and￿ published￿ Caltech-Cornell inspiral data is found to be smaller than $\pm 2\times 10^{-4}$ gravitational wave cycles over the entire span ($3000M$, corresponding￿ to 30 cycles) of the inspiral simulation. The dephasings between EOB and coalescence data are found to be smaller than: (i) $\pm 4\times 10^{-3}$ gravitational wave cycles over $730M$ (11 cycles), in the equal mass case, and (ii) $\pm 8\times 10^{-3}$ gravitational wave cycles over about $900M$ (17 cycles)￿ 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.

DATA: 15-04-2008