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Authors: Chris Van Den Broeck, Anand Sengupta

Date: Thu, 26 Oct 2006

Abstract: We investigate the effects on parameter estimation of including amplitude corrections to post-Newtonian (PN) gravitational waveforms for the quasi-circular, adiabatic inspiral of binary compact objects. The amplitude-corrected waveforms are superpositions of harmonics of the orbital phase. Their performance is compared with that of the restricted PN waveforms, which only have the dominant harmonic at twice the orbital phase, with no amplitude corrections. For concreteness we consider parameter estimation in the covariance matrix formalism for Advanced LIGO as well as a possible third-generation detector tentatively called EGO. We use the stationary phase approximation to the Fourier transform of waveforms at 2.5PN order in amplitude and in phase, with inclusion of spin-related contributions to the phasing up to 2PN order. It is found that the use of such high-order amplitude-corrected waveforms leads to a dramatic improvement in the quality of parameter estimation. With restricted waveforms the errors are steep functions of the total mass of the binary, and accurate parameter extraction is only possible for relatively light stellar mass binaries. By contrast, at distances of $\sim 100$ Mpc the amplitude-corrected waveforms allow for high-accuracy parameter extraction for total masses up to several hundred solar masses. Other qualitative advantages include the measurability of individual component masses (which are poorly determined with restricted waveforms), and the possibility of finding objects whose spin exceeds the Kerr bound.

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