Establish prior odds by estimating merger-rate fractions for quasi-circular precessing versus eccentric aligned-spin binaries

Identify and estimate astrophysical merger-rate fractions (and corresponding prior odds) for quasi-circular, spin-precessing binary black holes versus eccentric, aligned-spin binary black holes, enabling computation of odds ratios between these hypotheses in Bayesian model selection for gravitational-wave events.

Background

The odds ratio used in this paper requires prior odds derived from astrophysical rate estimates. While rates for eccentric versus quasi-circular aligned-spin populations were assembled, the authors did not consider odds for eccentric aligned-spin versus quasi-circular precessing due to a lack of rate estimates in the literature.

Providing such rate estimates would enable a more comprehensive comparison of hypotheses, reducing dependence on waveform-model limitations and improving event classification.