Generating approximate halo catalogues for blind challenges in precision cosmology

Journal Article · 02 March 2019 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stz600 · OSTI ID:1498594

Garrison, Lehman H.  ^[1]; Eisenstein, Daniel J. ^[1]

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1. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

We present a method for generating suites of dark matter halo catalogues with only a few N-body simulations, focusing on making small changes to the underlying cosmology of a simulation with high precision. In the context of blind challenges, this allows us to re-use a simulation by giving it a new cosmology after the original cosmology is revealed. Starting with full N-body realizations of an original cosmology and a target cosmology, we fit a transfer function that displaces haloes in the original so that the galaxy/HOD power spectrum matches that of the target cosmology. This measured transfer function can then be applied to a new realization of the original cosmology to create a new realization of the target cosmology. For a 1 percent change in σ₈, we achieve 0.1 percent accuracy to |$$k = 1\, h\, \mathrm{Mpc}^{-1}$$| in the real-space power spectrum; this degrades to 0.3 percent when the transfer function is applied to a new realization. Here, we achieve similar accuracy in the redshift-space monopole and quadrupole. In all cases, the result is better than the sample variance of our |$$1.1\, h^{-1}\, \mathrm{Gpc}$$| simulation boxes.

• Research Organization: Harvard Univ., Cambridge, MA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Science Foundation (NSF)
• Grant/Contract Number: SC0013718; AST-1313285
• OSTI ID: 1498594
• Alternate ID(s): OSTI ID: 1612028
• Journal Information: Monthly Notices of the Royal Astronomical Society, Vol. 485, Issue 2; ISSN 0035-8711
• Publisher: Royal Astronomical SocietyCopyright Statement
• Country of Publication: United States
• Language: English