Structure formation from non-Gaussian initial conditions: Multivariate biasing, statistics, and comparison with N-body simulations

Journal Article · Mon Mar 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.063530· OSTI ID:21409392

Giannantonio, Tommaso; Porciani, Cristiano ^[1]

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1. Argelander-Institut fuer Astronomie der Universitaet Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany)

We study structure formation in the presence of primordial non-Gaussianity of the local type with parameters f{sub NL} and g{sub NL}. We show that the distribution of dark-matter halos is naturally described by a multivariate bias scheme where the halo overdensity depends not only on the underlying matter density fluctuation {delta} but also on the Gaussian part of the primordial gravitational potential {phi}. This corresponds to a non-local bias scheme in terms of {delta} only. We derive the coefficients of the bias expansion as a function of the halo mass by applying the peak-background split to common parametrizations for the halo mass function in the non-Gaussian scenario. We then compute the halo power spectrum and halo-matter cross spectrum in the framework of Eulerian perturbation theory up to third order. Comparing our results against N-body simulations, we find that our model accurately describes the numerical data for wave numbers k{<=}0.1-0.3h Mpc{sup -1} depending on redshift and halo mass. In our multivariate approach, perturbations in the halo counts trace {phi} on large scales, and this explains why the halo and matter power spectra show different asymptotic trends for k{yields}0. This strongly scale-dependent bias originates from terms at leading order in our expansion. This is different from what happens using the standard univariate local bias where the scale-dependent terms come from badly behaved higher-order corrections. On the other hand, our biasing scheme reduces to the usual local bias on smaller scales, where |{phi}| is typically much smaller than the density perturbations. We finally discuss the halo bispectrum in the context of multivariate biasing and show that, due to its strong scale and shape dependence, it is a powerful tool for the detection of primordial non-Gaussianity from future galaxy surveys.

• OSTI ID: 21409392
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 6; Other Information: DOI: 10.1103/PhysRevD.81.063530; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMPTOTIC SOLUTIONS
COMPARATIVE EVALUATIONS
CORRECTIONS
DENSITY
DETECTION
DISTRIBUTION
DISTURBANCES
EXPANSION
FLUCTUATIONS
GALAXIES
GRAVITATION
MASS
MULTIVARIATE ANALYSIS
NONLUMINOUS MATTER
PERTURBATION THEORY
RED SHIFT
SIMULATION
SPECTRA
EVALUATION
MATHEMATICAL SOLUTIONS
MATHEMATICS
MATTER
PHYSICAL PROPERTIES
STATISTICS
VARIATIONS