Advanced methods for parameter estimation of gravitational wave sources*

Following recent developments in waveform modeling, state-of-the-art models of compact binary coalescences now incorporate higher order harmonics and generically oriented spins. These improvements increased the diversity of waveform morphologies and the parameter space dimensionality, rendering computational cost a major hurdle for parameter estimation studies.

The relative binning (heterodyned likelihood) algorithm allows to accurately represent a waveform at low frequency resolution, in terms of its departure from a (fixed) high resolution reference waveform. I will describe a generalization of this method to waveforms with higher order harmonics.

I will also introduce a set of analytic, invertible coordinate transformations that remove several degeneracies and multimodalities typically encountered in source parameter measurements. These coordinates facilitate sampling posterior distributions and, most interestingly, offer new insights on the occurrence of in-plane spins in nature.