• DOI:10.1103/PhysRevD.105.083517
• Corpus ID: 238856905

Full-shape cosmology analysis of the SDSS-III BOSS galaxy power spectrum using an emulator-based halo model: A 5% determination of σ8

@article{Kobayashi2022FullshapeCA,
  title={Full-shape cosmology analysis of the SDSS-III BOSS galaxy power spectrum using an emulator-based halo model: A 5\% determination of 
$\sigma$8},
  author={Yosuke Kobayashi and Takahiro Nishimichi and Masahiro Takada and Hironao Miyatake},
  journal={Physical Review D},
  year={2022}
}

• Yosuke Kobayashi, T. Nishimichi, +1 author H. Miyatake
• Published 13 October 2021
• Physics
• Physical Review D

We present the results obtained from the full-shape cosmology analysis of the redshift-space power spectra for 4 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 ΛCDM cosmology. In our cosmology inference, we use the monopole, quadrupole and hexadecapole moments of the redshift-space power spectrum and include 7 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 Ω 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 max = 0 . 25 h Mpc − 1 , we find Ω m = 0 . 301 +0 . 012 − 0 . 011 , H 0 = 68 . 2 ± 1 . 4 km s − 1 Mpc − 1 , and σ 8 = 0 . 786 +0 . 036 − 0 . 037 , 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 (cid:39) 0 . 2 h 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 σ statistical uncertainties.