Ding, Zhejie;
Chuang, Chia-Hsun;
Yu, Yu;
Garrison, Lehman H;
Bayer, Adrian E;
Feng, Yu;
Modi, Chirag;
... Poppett, Claire; + view all
(2022)
The DESI N-body Simulation Project - II. Suppressing sample variance with fast simulations.
Monthly Notices of the Royal Astronomical Society
, 514
(3)
pp. 3308-3328.
10.1093/mnras/stac1501.
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Abstract
Dark Energy Spectroscopic Instrument (DESI) will construct a large and precise three-dimensional map of our Universe. The survey effective volume reaches ∼20h−3Gpc3. It is a great challenge to prepare high-resolution simulations with a much larger volume for validating the DESI analysis pipelines. ABACUSSUMMIT is a suite of high-resolution dark-matter-only simulations designed for this purpose, with 200h−3Gpc3 (10 times DESI volume) for the base cosmology. However, further efforts need to be done to provide a more precise analysis of the data and to cover also other cosmologies. Recently, the CARPool method was proposed to use paired accurate and approximate simulations to achieve high statistical precision with a limited number of high-resolution simulations. Relying on this technique, we propose to use fast quasi-N-body solvers combined with accurate simulations to produce accurate summary statistics. This enables us to obtain 100 times smaller variance than the expected DESI statistical variance at the scales we are interested in, e.g. k<0.3hMpc−1 for the halo power spectrum. In addition, it can significantly suppress the sample variance of the halo bispectrum. We further generalize the method for other cosmologies with only one realization in ABACUSSUMMIT suite to extend the effective volume ∼20 times. In summary, our proposed strategy of combining high-fidelity simulations with fast approximate gravity solvers and a series of variance suppression techniques sets the path for a robust cosmological analysis of galaxy survey data.
| Type: | Article |
|---|---|
| Title: | The DESI N-body Simulation Project - II. Suppressing sample variance with fast simulations |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stac1501 |
| Publisher version: | https://doi.org/10.1093/mnras/stac1501 |
| Language: | English |
| Additional information: | © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, methods: statistical, galaxies: haloes, cosmology: theory, large-scale structure of Universe, DARK-MATTER, MOCK CATALOGS, GALAXIES, SCHEME |
| UCL classification: | 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 Physics and Astronomy UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10151333 |
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