Population-informed priors in gravitational-wave astronomy [CL]

http://arxiv.org/abs/2108.02462


We describe a Bayesian formalism for analyzing individual gravitational-wave events in light of the rest of an observed population. This analysis reveals how the idea of a population-informed prior'' arises naturally from a suitable marginalization of an underlying hierarchical Bayesian model which consistently accounts for selection effects. Our formalism naturally leads to the presence ofleave-one-out” distributions which include subsets of events. This differs from other approximations, also known as empirical Bayes methods, which effectively double count one or more events. We design a double-reweighting post-processing strategy that uses only existing data products to reconstruct the resulting population-informed posterior distributions. Although the correction we highlight is an important conceptual point, we find it has a limited impact on the current catalog of gravitational-wave events. Our approach further allows us to study, for the first time in the gravitational-wave literature, correlations between the parameters of individual events and those of the population.

Read this paper on arXiv…

C. Moore and D. Gerosa
Mon, 9 Aug 21
44/51

Comments: 11 pages, 5 figures + supplementary material