Improvements in cosmological constraints from breaking growth degeneracy
In: Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 642, pp.A116. ⟨10.1051/0004-6361/202038409⟩ Perenon, L, Ilić, S, Maartens, R & Cruz-Dombriz, A D L 2020, ' Improvements in cosmological constraints from breaking growth degeneracy ', Astronomy and Astrophysics, vol. 642, A116, pp. 1-8 https://doi.org/10.1051/0004-6361/202038409
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Zugriff:
The key probes of the growth of large-scale structure are its rate $f$ and amplitude $\sigma_8$. Redshift space distortions in the galaxy power spectrum allow us to measure only the combination $f\sigma_8$, which can be used to constrain the standard cosmological model or alternatives. By using measurements of the galaxy-galaxy lensing cross-correlation spectrum or of the galaxy bispectrum, it is possible to break the $f\sigma_8$ degeneracy and obtain separate estimates of $f$ and $\sigma_8$ from the same galaxy sample. Currently there are only a handful of such separate measurements, but even this allows for improved constraints on cosmological models. We explore how having a larger and more precise sample of such measurements in the future could constrain further cosmological models. We consider what can be achieved by a future nominal sample that delivers a $\sim 1\%$ constraint on $f$ and $\sigma_8$ separately, compared to the case with a similar precision on the combination $f\sigma_8$. For the six cosmological parameters of $\Lambda$CDM, we find improvements of $\sim\! 5$--$50\%$ on their constraints. For modified gravity models in the Horndeski class, the improvements on these standard parameters are $\sim\! 0$--$15\%$. However, the precision on the sum of neutrino masses improves by 65\% and there is a significant increase in the precision on the background and perturbation Horndeski parameters.
Comment: 9 pages, 4 figures, 5 tables. Version accepted by Astron. Astrophys
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Improvements in cosmological constraints from breaking growth degeneracy
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Autor/in / Beteiligte Person: | Ilić, Stéphane ; Maartens, Roy ; Perenon, Louis ; Álvaro de la Cruz-Dombriz ; Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)) ; Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP) ; Université Paris-Seine-Université Paris-Seine-Observatoire de Paris ; Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) ; Institut de recherche en astrophysique et planétologie (IRAP) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3) ; Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP) ; Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS) |
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Quelle: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 642, pp.A116. ⟨10.1051/0004-6361/202038409⟩ Perenon, L, Ilić, S, Maartens, R & Cruz-Dombriz, A D L 2020, ' Improvements in cosmological constraints from breaking growth degeneracy ', Astronomy and Astrophysics, vol. 642, A116, pp. 1-8 https://doi.org/10.1051/0004-6361/202038409 |
Veröffentlichung: | HAL CCSD, 2020 |
Medientyp: | unknown |
ISSN: | 0004-6361 (print) |
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