Gravitational Wave mergers as tracers of Large Scale Structures

Abstract

Clustering measurements of Gravitational Wave (GW) mergers in Luminosity Distance Space can be used in the future as a powerful tool for Cosmology. We consider tomographic measurements of the Angular Power Spectrum of mergers both in an Einstein Telescope-like detector network and in some more advanced scenarios (more sources, better distance measurements, better sky localization). We produce Fisher forecasts for both cosmological (matter and dark energy) and merger bias parameters. Our fiducial model for the number distribution and bias of GW events is based on results from hydrodynamical simulations. The cosmological parameter forecasts with Einstein Telescope are less powerful than those achievable in the near future via galaxy clustering observations with, e.g., Euclid. However, in the more advanced scenarios we see significant improvements. Moreover, we show that bias can be detected at high statistical significance. Regardless of the specific constraining power of different experiments, many aspects make this type of analysis interesting anyway. For example, compact binary mergers detected by Einstein Telescope will extend up to very high redshifts, particularly for binary black holes. Furthermore, Luminosity Distance Space Distortions in the GW analysis have a different structure with respect to Redshift-Space Distortions in galaxy catalogues. Finally, measurements of the bias of GW mergers can provide useful insight into their physical nature and properties.

Gravitational waves × HI intensity mapping: cosmological and astrophysical applications

“…with a = 0.948, b = −0.553, c = 0.996, d = 1.034. The authors of reference [46] find a general agreement to the behaviour of these prescriptions, up to the redshift range considered in this work. Note that this determination of the bias, as well as the dN/dz, may also depend on other important astrophysical parameters, such as IMF and metallicity, and on the considered merging channel, such as isolated binaries, dynamical merger in stellar and nuclear stars clusters, mergers of PopIII stars, etc.…”

Listening to the Universe with Next Generation Ground-Based Gravitational-Wave Detectors

“…GW catalogs compiled by other groups [19][20][21][22][23] have largely confirmed the population of coalescing compact bina-These discoveries have already made a massive impact on our understanding of different tenets of astrophysics, fundamental physics, and cosmology. They have allowed a first glimpse into the dynamics of strongly curved spacetimes and the validity of general relativity (GR) in unexplored regimes of the theory [29][30][31][32][33][34], raised deeper questions on the formation mechanisms and evolutionary scenarios of compact objects [16,18,[35][36][37][38][39][40][41][42][43][44][45][46], provided a new tool for measuring cosmic distances that will help in precision cosmology [47,48] and in mapping the large scale structure of the Universe [49][50][51][52], and brought to bear a novel approach to determine the structure and properties of NSs to help in the exploration of the dense matter equation of state which governs the dynamics of NS cores [53][54][55][56][57][58][59][60][61][62]. The second part of the third observing run saw the discovery of two neutron star-black hole binaries, GW200105...…”

Parameter estimation with non stationary noise in gravitational waves data

“…The ever growing catalog enables us to answer important questions about the intrinsic population properties of the sources; these include the mass function, spin distribution, and redshift distribution (Abbott et al 2021b). By inferring the localization volumes of individual GW merger events with the help of parameter estimation (PE) methods, and by cross correlating the localization volumes with galaxy catalogs, one can also estimate the cosmological parameters such as the Hubble constant (Abbott et al 2021c), and large scale distribution of matter (Vijaykumar et al 2020;Mukherjee et al 2021a;Libanore et al 2021;Mukherjee et al 2021b;Caas-Herrera et al 2021). The reach of thirdgeneration detectors also implies a large population of loud BNS mergers which will be prime candidates for electromagnetic-followup campaigns.…”