Cosmological model selection from standard siren detections by third-generation gravitational wave observatories

Abstract

The multi-messenger observation of GW170817 enabled the first historic measurement of the Hubble constant via a standard siren , so-called in analogy to standard candles that enabled the measurement of the luminosity distance versus redshift relationship at small redshift. In the next decades, third-generation observatories are expected to detect hundreds to thousand of gravitational wave events from compact binary coalescences with potentially a joint electromagnetic counterpart. In the present work, we show how future standard siren detections can be used within the framework of Bayesian model selection to discriminate between cosmological models differing by the parameterization of the late-time acceleration. In particular, we found quantitative conditions for the standard Λ CDM model to be favored with respect to other models with varying dark energy content, by reducing the uncertainty in the gravitational determination of the luminosity distance with respect to current expectations.