Inspiral waveforms for spinning compact binaries in a new precessing convention

Abstract

It is customary to use a precessing convention, based on Newtonian orbital angular momentum LN, to model inspiral gravitational waves from generic spinning compact binaries. A key feature of such a precessing convention is its ability to remove all spin precession induced modulations from the orbital phase evolution. However, this convention usually employs a postNewtonian (PN) accurate precessional equation, appropriate for the PN accurate orbital angular momentum L, to evolve the LN-based precessing source frame. This motivated us to develop inspiral waveforms for spinning compact binaries in a precessing convention that explicitly use L to describe the binary orbits. Our approach introduces certain additional 3PN order terms in the orbital phase and frequency evolution equations with respect to the usual LN-based implementation of the precessing convention. The implications of these additional terms are explored by computing the match between inspiral waveforms that employ L and LN-based precessing conventions. We found that the match estimates are smaller than the optimal value, namely 0.97, for a non-negligible fraction of unequal mass spinning compact binaries.