SÉMINAIRE DU GRECO
"New Class of Post Newtonian Waveform Templates for Inspiralling Compact Binaries" |
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Bala Iyer |
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Post-Newtonian expansions of the binding energy and gravitational wave flux truncated at the same relative post-Newtonian order form the basis of the standard adiabatic approximation to the phasing of gravitational waves from inspiralling compact binaries. Viewed in terms of the dynamics of the binary, the standard approximation is equivalent to neglecting certain conservative post-Newtonian terms in the acceleration. We propose a new complete adiabatic approximant constructed from the energy and flux functions so that, effectively the approximation corresponds to the dynamics where there are no missing post-Newtonian terms in the acceleration. We compare the overlaps of the standard and complete adiabatic templates with the exact waveform in the adiabatic approximation of a test-mass motion in the Schwarzschild spacetime for the LIGO VIRGO and the Advanced LIGO noise spectra. It is found that the complete adiabatic approximants lead to a remarkable improvement in the effectualness at PN order smaller than 3PN, while standard approximants of order greater or equal to than 3PN perform as well as the complete approximants for the construction of effectual templates. Faithfulness of complete approximants is better than that of standard approximants except for a few post-Newtonian orders. Standard and complete approximants beyond the adiabatic approximation are also studied using the Lagrangian templates of Buonanno, Chen and Vallisneri. |
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jeudi 19 mai 2005 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
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