Angular velocity of gravitational radiation from precessing binaries and the corotating frame

Understand

This paper defines an angular velocity for time-dependent functions on the sphere, and applies it to gravitational waveforms from compact binaries.

• Because it is geometrically meaningful and has a clear physical motivation, the angular velocity is uniquely useful in helping to solve an important---and largely ignored---problem in models of compact binaries: the inverse problem of deducing the physical parameters of a system from the gravitational waves alone.
• It is also used to define the corotating frame of the waveform.
• When decomposed in this frame, the waveform has no rotational dynamics and is therefore as slowly evolving as possible.