An emulation-based model for the projected correlation function

Abstract

Data from the ongoing \textit{Euclid} survey will map out billions of galaxies in the Universe, covering more than a third of the sky. This data will provide a wealth of information about the large-scale structure (LSS) of the Universe and will have a significant impact on cosmology in the coming years. In this paper, we introduce an emulator-based halo model approach to forward model the relationship between cosmological parameters and the projected galaxy-galaxy two-point correlation function (2PCF). Utilizing the large \textsc{AbacusSummit} simulation suite, we emulate the 2PCF by generating mock-galaxy catalogues within the Halo Occupation Distribution (HOD) framework. Our emulator is designed to predict the 2PCF over scales $0.1\le r/(h^{-1}\text{Mpc})\le 105$, from which we derive the projected correlation function, independent of redshift space distortions. We demonstrate that the emulator accurately predicts the projected correlation function over scales $0.5\le r_{\perp }/(h^{-1}\text{Mpc})\le 40$, given a set of cosmological and HOD parameters. This model is then employed in a parameter inference analysis, showcasing its ability to constrain cosmological parameters. Our findings indicate that while the projected correlation function places weak constraints on several cosmological parameters due to its intrinsic lack of information, additional clustering statistics are necessary to better probe the underlying cosmology. Despite the simplified covariance matrix used in the likelihood model, the posterior distributions of several cosmological parameters remain broad, underscoring the need for a more comprehensive approach.

10 pages, 5 figures

References in corpus (28)

• emcee: The MCMC Hammer
• Exploring the Expansion History of the Universe
• The 2dF Galaxy Redshift Survey: Power-spectrum analysis of the final dataset and cosmological implications
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory
• Theoretical Models of the Halo Occupation Distribution: Separating Central and Satellite Galaxies
• The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Overview and Early Data
• The WiggleZ Dark Energy Survey: Survey Design and First Data Release
• An accurate physical model for halo concentrations
• AbacusSummit: A Massive Set of High-Accuracy, High-Resolution $N$-Body Simulations
• Halo Occupation Distribution Modeling of Clustering of Luminous Red Galaxies
• Dark Quest. I. Fast and Accurate Emulation of Halo Clustering Statistics and Its Application to Galaxy Clustering
• Corrfunc --- A Suite of Blazing Fast Correlation Functions on the CPU
• The Aemulus Project III: Emulation of the Galaxy Correlation Function
• Redshift-Space Clustering of SDSS Galaxies --- Luminosity Dependence, Halo Occupation Distribution, and Velocity Bias
• SMT 2.0: A Surrogate Modeling Toolbox with a focus on Hierarchical and Mixed Variables Gaussian Processes
• Full-shape cosmology analysis of SDSS-III BOSS galaxy power spectrum using emulator-based halo model: a $5\%$ determination of ${\sigma }_8$
• Cosmic Emulation: Fast Predictions for the Galaxy Power Spectrum
• AbacusHOD: A highly efficient extended multi-tracer HOD framework and its application to BOSS and eBOSS data
• The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: modeling of the luminosity and colour dependence in the Data Release 10
• Constraints on Assembly Bias from Galaxy Clustering
• \textsc{CompaSO}: A new halo finder for competitive assignment to spherical overdensities
• The Aemulus Project V: Cosmological constraint from small-scale clustering of BOSS galaxies
• Cosmological inference from emulator based halo model I: Validation tests with HSC and SDSS mock catalogs
• The Aemulus Project VI: Emulation of beyond-standard galaxy clustering statistics to improve cosmological constraints
• Galaxy clustering from the bottom up: A Streaming Model emulator I
• Galaxy Clustering in the Mira-Titan Universe I: Emulators for the redshift space galaxy correlation function and galaxy-galaxy lensing
• Cosmological parameters from the joint analysis of Density Split and Second Order Statistics: an Emulator based on the Halo Occupation Distribution