Mitigating the noise of DESI mocks using analytic control variates

Abstract

In order to address fundamental questions related to the expansion history of the Universe and its primordial nature with the next generation of galaxy experiments, we need to model reliably large-scale structure observables such as the correlation function and the power spectrum. Cosmological $N$-body simulations provide a reference through which we can test our models, but their output suffers from sample variance on large scales. Fortunately, this is the regime where accurate analytic approximations exist. To reduce the variance, which is key to making optimal use of these simulations, we can leverage the accuracy and precision of such analytic descriptions using Control Variates (CV). The power of control variates stems from utilizing inexpensive but highly correlated surrogates of the statistics one wishes to measure. The stronger the correlation between the surrogate and the statistic of interest, the larger the variance reduction delivered by the method. We apply two control variate formulations to mock catalogs generated in anticipation of upcoming data from the Dark Energy Spectroscopic Instrument (DESI) to test the robustness of its analysis pipeline. Our CV-reduced measurements offer a factor of 5-10 improvement in the measurement error compared with the raw measurements. We explore the relevant properties of the galaxy samples that dictate this reduction and comment on the improvements we find on some of the derived quantities relevant to Baryon Acoustic Oscillation (BAO) analysis. We also provide an optimized package for computing the power spectra and other two-point statistics of an arbitrary galaxy catalog as well as a pipeline for obtaining CV-reduced measurements on any of the AbacusSummit cubic box outputs. We make our scripts publicly available and report a speed improvement of $\sim$10 for a grid size of $N_{\mathrm{mesh}}=256^3$ compared with \texttt{nbodykit}.

arXiv comment17 pages, 9 figures, public package (for power spectrum and control variates estimation)

References in corpus (54)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 10 and 11 galaxy samples
• The DESI Experiment Part I: Science,Targeting, and Survey Design
• Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
• Cosmology and fundamental physics with the Euclid satellite
• A 2% Distance to z=0.35 by Reconstructing Baryon Acoustic Oscillations - I : Methods and Application to the Sloan Digital Sky Survey
• The Effective Field Theory of Cosmological Large Scale Structures
• Renormalized Cosmological Perturbation Theory
• The Cosmic Linear Anisotropy Solving System (CLASS) I: Overview
• Improving Cosmological Distance Measurements by Reconstruction of the Baryon Acoustic Peak
• Resumming Cosmological Perturbations via the Lagrangian Picture: One-loop Results in Real Space and in Redshift Space
• Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
• On the Robustness of the Acoustic Scale in the Low-Redshift Clustering of Matter
• The DESI Experiment, a whitepaper for Snowmass 2013
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in Fourier-space
• Second Order Power Spectrum and Nonlinear Evolution at High Redshift
• The DESI Experiment Part II: Instrument Design
• Convolution Lagrangian perturbation theory for biased tracers
• The MICE Grand Challenge Lightcone Simulation I: Dark matter clustering
• AbacusSummit: A Massive Set of High-Accuracy, High-Resolution $N$-Body Simulations
• FastPM: a new scheme for fast simulations of dark matter and halos
• The BACCO Simulation Project: Exploiting the full power of large-scale structure for cosmology
• EZmocks: extending the Zel'dovich approximation to generate mock galaxy catalogues with accurate clustering statistics
• The Robotic Multi-Object Focal Plane System of the Dark Energy Spectroscopic Instrument (DESI)
• The MICE Grand Challenge Lightcone Simulation III: Galaxy lensing mocks from all-sky lensing maps
• Euclid preparation: II. The EuclidEmulator -- A tool to compute the cosmology dependence of the nonlinear matter power spectrum
• The MICE Grand Challenge Lightcone Simulation II: Halo and Galaxy catalogues
• A new analysis of galaxy 2-point functions in the BOSS survey, including full-shape information and post-reconstruction BAO
• An algorithm to build mock galaxy catalogues using MICE simulations
• A Lagrangian effective field theory
• Prime Focus Spectrograph (PFS) for the Subaru Telescope: Overview, recent progress, and future perspectives
• The $\text{Abacus}$ Cosmological $N$-body Code
• The Zeldovich approximation
• Constraining Anisotropic Baryon Oscillations
• Galaxy Power Spectrum Multipoles Covariance in Perturbation Theory
• A High-Fidelity Realization of the Euclid Code Comparison $N$-body Simulation with Abacus
• Reconstruction within the Zeldovich approximation
• AbacusHOD: A highly efficient extended multi-tracer HOD framework and its application to BOSS and eBOSS data
• \textsc{CompaSO}: A new halo finder for competitive assignment to spherical overdensities
• Modeling the reconstructed BAO in Fourier space
• Theoretical Systematics of Future Baryon Acoustic Oscillation Surveys
• CARPool: fast, accurate computation of large-scale structure statistics by pairing costly and cheap cosmological simulations
• Science Impacts of the SPHEREx All-Sky Optical to Near-Infrared Spectral Survey II: Report of a Community Workshop on the Scientific Synergies Between the SPHEREx Survey and Other Astronomy Observatories
• Large Synoptic Survey Telescope: Dark Energy Science Collaboration
• Hierarchical Pancaking: Why the Zel'dovich Approximation Describes Coherent Large-Scale Structure in N-Body Simulations of Gravitational Clustering
• WEAVE-QSO: A Massive Intergalactic Medium Survey for the William Herschel Telescope
• Combining galaxy and 21cm surveys
• Accurate predictions from small boxes: variance suppression via the Zel'dovich approximation
• Precision Redshift-Space Galaxy Power Spectra using Zel'dovich Control Variates
• The DESI $N$-body Simulation Project -- II. Suppressing sample variance with fast simulations
• Why is the Zel'dovich Approximation so Accurate?
• Unequal time correlators and the Zeldovich approximation
• Effective Field Theory for Large Scale Structure
• Buzzard to Cardinal: Improved Mock Catalogs for Large Galaxy Surveys

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• DESI 2024 III: Baryon Acoustic Oscillations from Galaxies and Quasars
• Baryon Acoustic Oscillation Theory and Modelling Systematics for the DESI 2024 results
• HOD-Dependent Systematics in Emission Line Galaxies for the DESI 2024 BAO analysis
• HOD-Dependent Systematics for Luminous Red Galaxies in the DESI 2024 BAO Analysis
• Variance Reduction via Simultaneous Importance Sampling and Control Variates Techniques Using Vegas
• Simulation budgeting for hybrid effective field theories
• Clustering analysis of medium-band selected high-redshift galaxies