nIFTy cosmology: Galaxy/halo mock catalogue comparison project on clustering statistics

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reservedWe present a comparison of major methodologies of fast generating mock halo or galaxy catalogues. The comparison is done for two-point (power spectrum and two-point correlation function in real and redshift space), and the three-point clustering statistics (bispectrum and three-point correlation function). The reference catalogues are drawn from the BigMultiDark N-body simulation. Both friend-of-friends (including distinct haloes only) and spherical overdensity (including distinct haloes and subhalos) catalogues have been used with the typical number density of a large volume galaxy surveys. We demonstrate that a proper biasing model is essential for reproducing the power spectrum at quasi-linear and even smaller scales. With respect to various clustering statistics, a methodology based on perturbation theory and a realistic biasing model leads to very good agreement with N-body simulations. However, for the quadrupole of the correlation function or the power spectrum, only the method based on semi-N-body simulation could reach high accuracy (1 per cent level) at small scales, i.e. r 0.15 h Mpc-1. Full N-body solutions will remain indispensable to produce reference catalogues. Nevertheless, we have demonstrated that the more efficient approximate solvers can reach a few per cent accuracy in terms of clustering statistics at the scales interesting for the large-scale structure analysis. This makes them useful for massive production aimed at covariance studies, to scan large parameter spaces, and to estimate uncertainties in data analysis techniques, such as baryon acoustic oscillation reconstruction, redshift distortion measurements, etcThe authors would like to express special thanks to the Instituto de Fisica Teorica (IFT-UAM/CSIC in Madrid) for its hospitality and support, via the Centro de Excelencia Severo Ochoa Program under Grant No. SEV-2012-0249, during the three-weekworkshop ‘nIFTy Cosmology’ where this work developed. We further acknowledge the financial support of the University of Western 2014 Australia Research Collaboration Award for ‘Fast Approximate Synthetic Universes for the SKA’, the ARC Centre of Excellence for All Sky Astrophysics (CAASTRO) grant number CE110001020, and the two ARC Discovery Projects DP130100117 and DP140100198. CC and FP were supported by the Spanish MICINNs Consolider- Ingenio 2010 Programme under grant MultiDark CSD2009-00064 and AYA2010-21231-C02-01 grant, and Spanish MINECOs Centro de Excelencia Severo Ochoa Programme under grant SEV-2012- 0249. CZ and CT acknowledges support from Tsinghua University, and 973 student programme No. 2013CB834906. CZ also thanks the support from the MultiDark summer student program to visit the Instituto de Física Teórica, (UAM/CSIC), Spain. AK is supported by the Ministerio de Economía y Competitividad (MINECO) in Spain through grant AYA2012-31101, as well as the Consolider- Ingenio 2010 Programme of the Spanish Ministerio de Ciencia e Innovación (MICINN) under grant MultiDark CSD2009-00064. He also acknowledges support from the Australian Research Council (ARC) grants DP130100117 and DP140100198. EM and PM have been supported by a FRA2012 grant of the University of Trieste, PRIN2010-2011 (J91J12000450001) from MIUR, and by Consorzio per la Fisica di Trieste. AI is supported by the JAE program grant from the Spanish National Science Council (CSIC). GY acknowledges support from the Spanish MINECO under research grants AYA2012-31101, FPA2012-34694, AYA2010-21231, Consolider Ingenio SyeC CSD2007-0050 and from Comunidad de Madrid under ASTROMADRID project (S2009/ESP-1496). VT and SG have been supported by the German Science Foundation under DFG grant GO563/23-1. FAM is supported by the Australian Research Council Centre of Excellence for All-Sky Astrophysics (CAASTRO) through project number CE11000102