Improved filters for gravitational waves from inspiraling compact binaries

The order of the post-Newtonian expansion needed to extract in a reliable and accurate manner the fully general relativistic gravitational wave signal from inspiraling compact binaries is explored. A class of approximate wave forms, called P-approximants, is constructed based on the following two inputs: ~a! the introduction of two new energy-type and flux-type functions e(v) and f (v), respectively, ~b! the systematic use of the Padé approximation for constructing successive approximants of e(v) and f (v). The new P-approximants are not only more effectual ~larger overlaps! and more faithful ~smaller biases! than the standard Taylor approximants, but also converge faster and monotonically. The presently available (v/c)-accurate post-Newtonian results can be used to construct P-approximate wave forms that provide overlaps with the exact wave form larger than 96.5%, implying that more than 90% of potential events can be detected with the aid of P-approximants as opposed to a mere 10–15 % that would be detectable using standard post-Newtonian approximants. @S0556-2821~98!00104-0#