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Title: Full-shape cosmology analysis of the SDSS-III BOSS galaxy power spectrum using an emulator-based halo model: A 5% determination of σ₈
Authors: Kobayashi, Yosuke
Nishimichi, Takahiro  KAKEN_id  orcid https://orcid.org/0000-0002-9664-0760 (unconfirmed)
Takada, Masahiro
Miyatake, Hironao
Author's alias: 小林, 洋祐
西道, 啓博
高田, 昌広
宮武, 広直
Keywords: Cosmological parameters
Cosmology
Large scale structure of the Universe
Gravitation, Cosmology & Astrophysics
Issue Date: Apr-2022
Publisher: American Physical Society (APS)
Journal title: Physical Review D
Volume: 105
Issue: 8
Thesis number: 083517
Abstract: We present the results obtained from the full-shape cosmology analysis of the redshift-space power spectra for four galaxy samples of the SDSS-III BOSS DR12 galaxy catalog over 0.2 < z < 0.75. For the theoretical template, we use an emulator that was built from an ensemble set of N-body simulations, which enables fast and accurate computation of the redshift-space power spectrum of "halos." Combining with the halo occupation distribution to model the galaxy-halo connection, we can compute the redshift-space power spectrum of BOSS-like galaxies in less than a CPU second, for an input model under flat Lambda CDM cosmology. In our cosmology inference, we use the monopole, quadrupole, and hexadecapole moments of the redshift-space power spectrum and include seven nuisance parameters, with broad priors, to model uncertainties in the galaxy-halo connection for each galaxy sample, but do not use any information on the abundance of galaxies. We demonstrate a validation of our analysis pipeline using the mock catalogs of BOSS-like galaxies, generated using different recipes of the galaxy-halo connection and including the assembly bias effect. Assuming weak priors on cosmological parameters, except for the BBN prior on Omega(b)h(2) and the CMB prior on n(s), we show that our model well reproduces the BOSS power spectra. Including the power-spectrum information up to k(m)(ax) = 0.25h Mpc(-1), we find Omega(m) = 0.301(-0.011)(+0.012), H-0 = 68.2 +/- 1.4 km s(-1) Mpc(-1), and sigma(8) = 0.786(-0.037)(+0.036) for the mode and 68% credible interval, after marginalization over galaxy-halo connection parameters. We find little improvement in the cosmological parameters beyond a maximum wavelength k(max) similar or equal to 0.2h Mpc(-1) due to the shot noise domination and marginalization of the galaxy-halo connection parameters. Our results are consistent with the Planck CMB results within 1 sigma statistical uncertainties.
Description: AIとスーパーコンピュータで広大な銀河地図を解読 --宇宙の成り立ちを決める物理量を精密に測定--. 京都大学プレスリリース. 2022-07-21.
Rights: © 2022 American Physical Society
URI: http://hdl.handle.net/2433/276731
DOI(Published Version): 10.1103/PhysRevD.105.083517
Related Link: https://www.kyoto-u.ac.jp/ja/research-news/2022-07-21-3
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