Contarini, S;
Verza, G;
Pisani, A;
Hamaus, N;
Sahlen, M;
Carbone, C;
Dusini, S;
... Poncet, M; + view all
(2022)
Euclid: Cosmological forecasts from the void size function.
Astronomy and Astrophysics
, 667
, Article A162. 10.1051/0004-6361/202244095.
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Abstract
The Euclid mission a with its spectroscopic galaxy survey covering a sky area over 15a 000 deg2 in the redshift range 0.9a <a za <a 1.8 a will provide a sample of tens of thousands of cosmic voids. This paper thoroughly explores for the first time the constraining power of the void size function on the properties of dark energy (DE) from a survey mock catalogue, the official Euclid Flagship simulation. We identified voids in the Flagship light-cone, which closely matches the features of the upcoming Euclid spectroscopic data set. We modelled the void size function considering a state-of-The art methodology: we relied on the volume-conserving (Vdn) model, a modification of the popular Sheth van de Weygaert model for void number counts, extended by means of a linear function of the large-scale galaxy bias. We found an excellent agreement between model predictions and measured mock void number counts. We computed updated forecasts for the Euclid mission on DE from the void size function and provided reliable void number estimates to serve as a basis for further forecasts of cosmological applications using voids. We analysed two different cosmological models for DE: The first described by a constant DE equation of state parameter, w, and the second by a dynamic equation of state with coefficients w0 and wa. We forecast 1I errors on w lower than 10% and we estimated an expected figure of merit (FoM) for the dynamical DE scenario FoMw0a waa =a 17 when considering only the neutrino mass as additional free parameter of the model. The analysis is based on conservative assumptions to ensure full robustness, and is a pathfinder for future enhancements of the technique. Our results showcase the impressive constraining power of the void size function from the Euclid spectroscopic sample, both as a stand-Alone probe, and to be combined with other Euclid cosmological probes.
| Type: | Article |
|---|---|
| Title: | Euclid: Cosmological forecasts from the void size function |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1051/0004-6361/202244095 |
| Publisher version: | https://doi.org/10.1051/0004-6361/202244095 |
| Language: | English |
| Additional information: | Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article is published in open access under the Subscribe-to-Open model. Subscribe to A&A to support open access publication. |
| Keywords: | Dark energy, cosmology: theory, galaxies: statistics, catalogs, surveys, methods: data analysis |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10162979 |
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