Quijote-png: The information content of the halo power spectrum and bispectrum
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Date
2023
Journal Title
Journal ISSN
Volume Title
Publisher
IOP Publishing
Abstract
We investigate how much can be learnt about four types of primordial non-Gaussianity (PNG) from small-scale
measurements of the halo field. Using the QUIJOTE-PNG simulations, we quantify the information content
accessible with measurements of the halo power spectrum monopole and quadrupole, the matter power spectrum,
the halo–matter cross spectrum, and the halo bispectrum monopole. This analysis is the first to include small,
nonlinear scales, up to kmax 0.5 h Mpc = -1
, and to explore whether these scales can break degeneracies with
cosmological and nuisance parameters making use of thousands of N-body simulations. We perform all the halo
measurements in redshift space with a single sample comprised of all halos with mass >3.2 × 1013 h−1 Me. For
local PNG, measurements of the scale-dependent bias effect from the power spectrum using sample variance
cancellation provide significantly tighter constraints than measurements of the halo bispectrum. In this case
measurements of the small scales add minimal additional constraining power. In contrast, the information on
equilateral and orthogonal PNG is primarily accessible through the bispectrum. For these shapes, small-scale
measurements increase the constraining power of the halo bispectrum by up to 4×, though the addition of scales
beyond k ≈ 0.3 h Mpc−1 improves constraints largely through reducing degeneracies between PNG and the other
parameters.
Description
Keywords
Astronomy, Physics, Cosmology, Observational cosmology, Non-Gaussianity
Citation
Coulton, W. R. et al. (2023). Quijote-png: The information content of the halo power spectrum and bispectrum. Astrophysical Journal, 943(2), 178. 10.3847/1538-4357/aca7c1