TY - JOUR
T1 - Cosmological constraints from density-split clustering in the BOSS CMASS galaxy sample
AU - Paillas, Enrique
AU - Cuesta-Lazaro, Carolina
AU - Percival, Will J.
AU - Nadathur, Seshadri
AU - Cai, Yan-Chuan
AU - Yuan, Sihan
AU - Beutler, Florian
AU - Mattia, Arnaud de
AU - Eisenstein, Daniel J.
AU - Forero-Sanchez, Daniel
AU - Padilla, Nelson
AU - Pinon, Mathilde
AU - Ruhlmann-Kleider, Vanina
AU - Sánchez, Ariel G.
AU - Valogiannis, Georgios
AU - Zarrouk, Pauline
N1 - Submitted to MNRAS. Source code to generate the figures available in the captions
PY - 2024/4/25
Y1 - 2024/4/25
N2 - We present a clustering analysis of the BOSS DR12 CMASS galaxy sample, combining measurements of the galaxy two-point correlation function and density-split clustering down to a scale of $1\,h^{-1}{\rm Mpc}$. Our theoretical framework is based on emulators trained on high-fidelity mock galaxy catalogues that forward model the cosmological dependence of the clustering statistics within an extended-$\Lambda$CDM framework, including redshift-space and Alcock-Paczynski distortions. Our base-$\Lambda$CDM analysis finds $\omega_{\rm cdm} = 0.1201\pm 0.0022$, $\sigma_8 = 0.792\pm 0.034$, and $n_s = 0.970\pm 0.018$, corresponding to $f\sigma_8 = 0.462\pm 0.020$ at $z \approx 0.525$, which is in agreement with Planck 2018 predictions and various clustering studies in the literature. We test single-parameter extensions to base-$\Lambda$CDM, varying the running of the spectral index, the dark energy equation of state, and the density of massless relic neutrinos, finding no compelling evidence for deviations from the base model. We model the galaxy-halo connection using a halo occupation distribution framework, finding signatures of environment-based assembly bias in the data. We validate our pipeline against mock catalogues that match the clustering and selection properties of CMASS, showing that we can recover unbiased cosmological constraints even with a volume 84 times larger than the one used in this study.
AB - We present a clustering analysis of the BOSS DR12 CMASS galaxy sample, combining measurements of the galaxy two-point correlation function and density-split clustering down to a scale of $1\,h^{-1}{\rm Mpc}$. Our theoretical framework is based on emulators trained on high-fidelity mock galaxy catalogues that forward model the cosmological dependence of the clustering statistics within an extended-$\Lambda$CDM framework, including redshift-space and Alcock-Paczynski distortions. Our base-$\Lambda$CDM analysis finds $\omega_{\rm cdm} = 0.1201\pm 0.0022$, $\sigma_8 = 0.792\pm 0.034$, and $n_s = 0.970\pm 0.018$, corresponding to $f\sigma_8 = 0.462\pm 0.020$ at $z \approx 0.525$, which is in agreement with Planck 2018 predictions and various clustering studies in the literature. We test single-parameter extensions to base-$\Lambda$CDM, varying the running of the spectral index, the dark energy equation of state, and the density of massless relic neutrinos, finding no compelling evidence for deviations from the base model. We model the galaxy-halo connection using a halo occupation distribution framework, finding signatures of environment-based assembly bias in the data. We validate our pipeline against mock catalogues that match the clustering and selection properties of CMASS, showing that we can recover unbiased cosmological constraints even with a volume 84 times larger than the one used in this study.
KW - astro-ph.CO
KW - cosmological parameters
KW - large-scale structure of Universe
KW - UKRI
KW - STFC
KW - ST/T005009/2
U2 - 10.1093/mnras/stae1118
DO - 10.1093/mnras/stae1118
M3 - Article
SN - 0035-8711
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
ER -