Inferring cosmological parameters from galaxy and dark sirens cross-correlation

Journal of Cosmology and Astroparticle Physics, vol. 2026, pp. 095

Abstract

Abstract The number of observed gravitational wave (GW) events is growing fast thanks to rapidly improving detector sensitivities. GWs from compact binary coalescences like Black Holes or Neutron Stars behave like standard sirens and can be used as cosmological probes. To this aim, generally, the observation of an electromagnetic counterpart and the measurement of the redshift are needed. However, even when those are not available, it is still possible to exploit these “dark sirens” via statistical methods. In this work, we explore a method that exploits the information contained in the cross-correlation of samples of GW events with matter over-density tracers like galaxy catalogues. Contrary to other currently employed dark-sirens methods, this approach does not suffer from systematic errors related to the incompleteness of the galaxy catalogue. To further enhance the technique, we implement tomography in redshift space for the galaxy catalogue and luminosity distance space for the GWs. We simulate future data collected by the array of currently existing detectors, namely LIGO, Virgo, and KAGRA, as well as planned third-generation ones such as the Einstein Telescope and Cosmic Explorers. We cross-correlate these data with those from upcoming photometric galaxy surveys such as Euclid. We perform a sensitivity forecast employing a full-likelihood approach and explore the parameter space with Monte Carlo Markov Chains. We find that with this method, third-generation detectors will be able to determine the Hubble constant H 0 with an error of only 0.7%, which is enough to provide decisive information to shed light on the Hubble tension. Furthermore, for the other cosmological parameters, we find that the GWs and galaxy surveys information are highly complementary, and the use of both significantly improves the ability to constrain the underlying cosmology.

Authors 6

1. Giona Sala Aachen Institute for Theoretical Particle Physics and Cosmology

   RWTH Aachen University

   Affiliation as printed

   Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Sommerfeldstr. 16, D-52056 Aachen,

2. A. Cuoco

   Istituto Nazionale di Fisica Nucleare, Sezione di Torino · University of Turin

   Affiliation as printed

   Department of Physics, University of Torino, via P. Giuria 1, 10125 Torino,

   Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, 10125 Torino,

3. Julien Lesgourgues Aachen Institute for Theoretical Particle Physics and Cosmology

   RWTH Aachen University

   Affiliation as printed

   Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Sommerfeldstr. 16, D-52056 Aachen,

4. Konstantinos-Rafail Revis

   Paderborn University

   Affiliation as printed

   Department of Computer Science, Paderborn University, Warburger Str. 100, 33098, Paderborn,

5. Lorenzo Valbusa Dall'Armi

   Istituto Nazionale di Fisica Nucleare, Sezione di Pisa · University of Pisa

   Affiliation as printed

   Dipartimento di Fisica “Enrico Fermi”, Università di Pisa, Largo Bruno Pontecorvo 3, Pisa I-56127,

   INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, Pisa I-56127,

6. Santiago Casas Aachen Institute for Theoretical Particle Physics and Cosmology

   RWTH Aachen University · Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

   Affiliation as printed

   Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Sommerfeldstr. 16, D-52056 Aachen,

   Institute of Scientific Information, German Aerospace Center (DLR), Linder Höhe, D-51147 Köln,