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Waveforms for Binary Black Holes - Late Stages of In-spiral and Merger. B.S. Sathyaprakash LIGO-G010153-00-Z. Plan of the talk. Prospects for detecting binaries in initial interferometers Re-summed approach to GW phasing
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Waveforms for Binary Black Holes - Late Stages of In-spiral and Merger B.S. Sathyaprakash LIGO-G010153-00-Z LSC@Baton Rouge
Plan of the talk • Prospects for detecting binaries in initial interferometers • Re-summed approach to GW phasing • P-approximants - taming poorly convergent post-Newtonian expansion - Kerr case • Effective one-body - inspiral + plunge • Improvement in SNR by including plunge • Search strategy LSC@Baton Rouge
Sensitivity of first interferometers LSC@Baton Rouge
Signal-to-noise ratios for inspiralDamour, Iyer, Sathyaprakash 2000 LSC@Baton Rouge
Why bother using non-post-Newtonian waveformsDIS 98, 00; BD 98, 00; DJS 99; D 01 • Standard post-Newtonian expansion is very slowly convergent • Re-summation techniques are proven to be convergent and robust in the test mass limit • There are no alternatives to deal with physics close to, and beyond, the last stable orbit LSC@Baton Rouge
Exact GW flux - Kerr Case Tanaka 96 a=0.0, 0.25, 0.5, 0.75, 0.95 LSC@Baton Rouge
Post-Newtonian flux - Kerr caseTanaka et al 96 a=0.0, 0.25, 0.5, 0.75, 0.95 LSC@Baton Rouge
P-approximant flux - Kerr casePorter 01 a=0.0, 0.25, 0.5, 0.75, 0.95 LSC@Baton Rouge
Probing inspiral, plunge and merger LSC@Baton Rouge
Effective one-body approach Buonanno and Damour 98, 00 • Condense essential information about the dynamics in just one function - a radial potential: A(r=M/u) = 1-2u+2h u3 +a4(h,ws)u4 + … • The unknown coefficient ws, at 3PN level does not affect the overlaps severely • Allows the computation of the orbit beyond the last stable orbit up to r ~ 2.8M plunge LSC@Baton Rouge
EOB waveformBuonanno and Damour 00 LSC@Baton Rouge
EOB signal in frequency domainDamour, Iyer and Sathyaprakash 00 EOB Signals are wide-band LSC@Baton Rouge
Improvement in SNR while using EOB signalsDamour, Iyer and Sathyaprakash 01 LSC@Baton Rouge
Relative performance of different approximantsDamour, Iyer and Sathyaprakash 01 LSC@Baton Rouge
What waveforms should we use in our search codes? • LIGO-GEO network gives us a unique opportunity to make reliable detection of unreliable signals (4-way coincidence) • Low mass region, SPA or P-approximants • Our best candidates are BH-BH binaries • Binaries with 10-40 solar masses, number of templates required is about 10; employ EOB waveforms and expand search space around this family LSC@Baton Rouge