hide
Free keywords:
General Relativity and Quantum Cosmology, gr-qc,Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO
Abstract:
We outline the ``dark siren'' galaxy catalog method for cosmological
inference using gravitational wave (GW) standard sirens, clarifying some common
misconceptions in the implementation of this method. When a confident transient
electromagnetic counterpart to a GW event is unavailable, the identification of
a unique host galaxy is in general challenging. Instead, as originally proposed
by Schutz (1986), one can consult a galaxy catalog and implement a dark siren
statistical approach incorporating all potential host galaxies within the
localization volume. Trott & Hunterer 2021 recently claimed that this approach
results in a biased estimate of the Hubble constant, $H_0$, when implemented on
mock data, even if optimistic assumptions are made. We demonstrate explicitly
that, as previously shown by multiple independent groups, the dark siren
statistical method leads to an unbiased posterior when the method is applied to
the data correctly. We highlight common sources of error possible to make in
the generation of mock data and implementation of the statistical framework,
including the mismodeling of selection effects and inconsistent implementations
of the Bayesian framework, which can lead to a spurious bias.
