Exploring HOD-dependent systematics for the DESI 2024 Full-Shape galaxy clustering analysis
Abstract We analyse the robustness of the DESI 2024 cosmological inference from the full shape of the galaxy power spectrum to uncertainties in the Halo Occupation Distribution (HOD) model of the galaxy-halo connection and the choice of priors on nuisance parameters. We assess variations in the recovered cosmological parameters across a range of mocks populated with different HOD models and find that shifts are often greater than 20% of the expected statistical uncertainties from the DESI data. We encapsulate the effect of such shifts in terms of a systematic covariance term, C HOD , and an additional diagonal contribution quantifying the impact of our choice of nuisance parameter priors on the ability of the effective field theory (EFT) model to correctly recover the cosmological parameters of the simulations. These two covariance contributions are designed to be added to the usual covariance term, C stat , describing the statistical uncertainty in the power spectrum measurement, in order to fairly represent these sources of systematic uncertainty. This novel approach should be more general and robust to the choice of model or additional external datasets used in cosmological fits than the alternative approach of adding systematic uncertainties to the recovered marginalised parameter posteriors. We compare the approaches within the context of a fixed ΛCDM model and demonstrate that our method gives conservative estimates of the systematic uncertainty that nevertheless have little impact on the final posteriors obtained from DESI data.
Authors
- C. García-Quintero (ORCID: https://orcid.org/0000-0003-1481-4294)
- N. Findlay (ORCID: https://orcid.org/0009-0007-0716-3477)
- N. Palanque‐Delabrouille (ORCID: https://orcid.org/0000-0003-3188-784X)
- S. Nadathur (ORCID: https://orcid.org/0000-0001-9070-3102)
- D. Bianchi (ORCID: https://orcid.org/0000-0001-9712-0006)
- David J. Schlegel (ORCID: https://orcid.org/0000-0002-5042-5088)
- Ignasi Pérez-Ràfols (ORCID: https://orcid.org/0000-0001-6979-0125)
- Axel de la Macorra (ORCID: https://orcid.org/0000-0002-1769-1640)
- Héctor Gil-Marín (ORCID: https://orcid.org/0000-0003-0265-6217)
- S. Ahlen
- David J. Brooks (ORCID: https://orcid.org/0000-0003-2602-2518)
- M. E. Levi (ORCID: https://orcid.org/0000-0003-1887-1018)
- Giacomo Rossi (ORCID: https://orcid.org/0000-0001-8617-5984)
- Andreu Font-Ribera (ORCID: https://orcid.org/0000-0002-3033-7312)
- E. Sanchez
- J. Mena-Fernández (ORCID: https://orcid.org/0000-0001-9497-7266)
- G. Tarlé
- ChangHoon Hahn (ORCID: https://orcid.org/0000-0003-1197-0902)
- ENRIQUE GAZTAÑAGA (ORCID: https://orcid.org/0000-0001-9632-0815)
- G. Gutierrez (ORCID: https://orcid.org/0000-0003-0825-0517)
- B. A. Weaver
- Cullan Howlett (ORCID: https://orcid.org/0000-0002-1081-9410)
- Arjun T. Dey (ORCID: https://orcid.org/0000-0002-4928-4003)
- A. Rocher (ORCID: https://orcid.org/0000-0003-4349-6424)
- O. S. M. Alves
- Aaron Meisner (ORCID: https://orcid.org/0000-0002-1125-7384)
- Pauline Zarrouk (ORCID: https://orcid.org/0000-0002-7305-9578)
- M. Schubnell
- W.J Percival
- John Moustakas (ORCID: https://orcid.org/0000-0002-2733-4559)
- Arnaud de Mattia (ORCID: https://orcid.org/0000-0002-1700-2753)
- Hee‐Jong Seo (ORCID: https://orcid.org/0000-0002-6588-3508)
- M. Vargas-Magaña (ORCID: https://orcid.org/0000-0003-3841-1836)
- K. Honscheid
- T. Claybaugh (ORCID: https://orcid.org/0000-0002-5024-6987)
- P. Doel (ORCID: https://orcid.org/0000-0002-6397-4457)
- S. Cole
- J. E. Forero-Romero (ORCID: https://orcid.org/0000-0002-2890-3725)
- R. Miquel
- S. Juneau (ORCID: https://orcid.org/0000-0002-0000-2394)
- K. Fanning (ORCID: https://orcid.org/0000-0001-8996-4874)
- D. Sprayberry
Institutions
- Boston University (US)
- Institució Catalana de Recerca i Estudis Avançats (ES)
- Fermi National Accelerator Laboratory (US)
- Hiroshima Shudo University (JP)
- Harvard University (US)
- High Energy Accelerator Research Organization (JP)
- University of Waterloo (CA)
- The University of Queensland (AU)
- Perimeter Institute (CA)
- Institute for High Energy Physics (ES)
- University of Milan (IT)
- University of Michigan (US)
- Regional Municipality of Waterloo (CA)
- Sejong University (KR)
- National Solar Observatory (US)
- Institut d'Estudis Espacials de Catalunya (ES)
- Kavli Institute for Particle Astrophysics and Cosmology (US)
- Menlo School (US)
- Institut Català de Ciències del Clima (ES)
- Laboratoire de Physique Nucléaire et de Hautes Énergies (FR)
- Indiana Cancer Consortium (US)
- Michigan United (US)
- Unidades Centrales Científico-Técnicas (ES)
- Institut Cartogràfic i Geològic de Catalunya (ES)
- Laboratoire de Physique Subatomique et de Cosmologie (FR)
- Mylan (Switzerland) (CH)
- Institut de Recherche sur les Lois Fondamentales de l'Univers (FR)
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (ES)
- State Library of Ohio (US)
- University College London (GB)
- École Polytechnique Fédérale de Lausanne (CH)
- University of Portsmouth (GB)
- Universidad Nacional Autónoma de México (MX)
- Siena College (US)
- Universitat Politècnica de Catalunya (ES)
Publication Details
- Journal
- Journal of Cosmology and Astroparticle Physics
- Published
- 2025-09-01
- DOI
- https://doi.org/10.1088/1475-7516/2025/09/007
- Citations
- 4
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 4.62
Funders
- National Science Foundation
- U.S. Department of Energy
- National Aeronautics and Space Administration
- Gordon and Betty Moore Foundation
- University of Portsmouth
- Space Telescope Science Institute
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives
- Office of Science
- Science and Technology Facilities Council
- Division of Astronomical Sciences