The initial shear field in models with primordial local non-Gaussianity and implications for halo and void abundances

Abstract

We generalize Doroshkevich's celebrated formulae for the eigenvalues of the initial shear field associated with Gaussian statistics to the local non-Gaussian f_{nl} model. This is possible because, to at least second order in f_{nl}, distributions at fixed overdensity are unchanged from the case f_{nl}=0. We use this generalization to estimate the effect of f_{nl}\ne 0 on the abundance of virialized halos. Halo abundances are expected to be related to the probability that a certain quantity in the initial fluctuation field exceeds a threshold value, and we study two choices for this variable: it can either be the sum of the eigenvalues of the initial deformation tensor (the initial overdensity), or its smallest eigenvalue. The approach based on a critical overdensity yields results which are in excellent agreement with numerical measurements. We then use these same methods to develop approximations describing the sensitivity of void abundances on f_{nl}. While a positive f_{nl} produces more extremely massive halos, it makes fewer extremely large voids. Its effect thus is qualitatively different from a simple rescaling of the normalisation of the density fluctuation field σ_8. Therefore, void abundances furnish complementary information to cluster abundances, and a joint comparison of both might provide interesting constraints on primordial non-Gaussianity.

16 pages, 8 figures, match version accepted by MNRAS

References in corpus (19)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Ahf: Amiga's Halo Finder
• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Effects of Scale-Dependent Non-Gaussianity on Cosmological Structures
• Detection of primordial non-Gaussianity (fNL) in the WMAP 3-year data at above 99.5% confidence
• The bispectrum of galaxies from high-redshift galaxy surveys: primordial non-Gaussianity and non-linear galaxy bias
• Primordial non-gaussianity, statistics of collapsed objects, and the Integrated Sachs-Wolfe effect
• Primordial non-Gaussianity: large-scale structure signature in the perturbative bias model
• Non-Gaussianities in New Ekpyrotic Cosmology
• Limits on Primordial Non-Gaussianity from Minkowski Functionals of the WMAP Temperature Anisotropies
• Signature of Primordial Non-Gaussianity on Matter Power Spectrum
• Environmental dependence in the ellipsoidal collapse model
• A high-significance detection of non-Gaussianity in the WMAP 5-year data using directional spherical wavelets
• The Void Abundance with Non-Gaussian Primordial Perturbations
• Optimal dataset combining in f_nl constraints from large scale structure in an idealised case
• Renormalized Newtonian Cosmic Evolution with Primordial Non-Gaussianity
• Statistical properties of the linear tidal shear
• The nonlinear probability distribution function in models with local primordial non-Gaussianity
• Ellipsoidal collapse and the redshift space probability distribution function of dark matter

Cited by in corpus (29)

• Constraining Running Non-Gaussianity
• Signature of primordial non-Gaussianity of phi^3-type in the mass function and bias of dark matter haloes
• Large-Scale Clustering of Cosmic Voids
• Primordial non-Gaussianity in the large scale structure of the Universe
• A hierarchy of voids: More ado about nothing
• Unveiling the Dynamics of the Universe
• The Hunt for Primordial Interactions in the Large Scale Structures of the Universe
• Voids in Modified Gravity Reloaded: Eulerian Void Assignment
• Measuring the neutrino mass from future wide galaxy cluster catalogues
• Excursion Sets and Non-Gaussian Void Statistics
• Hunting high and low: Disentangling primordial and late-time non-Gaussianity with cosmic densities in spheres
• A Study of High-Order Non-Gaussianity with Applications to Massive Clusters and Large Voids
• The Matter Bispectrum in N-body Simulations with non-Gaussian Initial Conditions
• Testing spherical evolution for modelling void abundances
• Conditional Probabilities in the Excursion Set Theory. Generic Barriers and non-Gaussian Initial Conditions
• Computation of the Halo Mass Function Using Physical Collapse Parameters: Application to Non-Standard Cosmologies
• Non-Gaussian halo abundances in the excursion set approach with correlated steps
• On the initial shear field of the cosmic web
• Modelling the shapes of the largest gravitationally bound objects
• Constraining Primordial Non-Gaussianity with Moments of the Large Scale Density Field
• The pairwise velocity probability density function in models with local primordial non-Gaussianity
• The nonlinear redshift space probability distribution function in models with local primordial non-Gaussianity
• Scale-dependent Bias from the Reconstruction of Non-Gaussian Distributions
• On the anisotropic density distribution on large scales
• The LUX Dark Matter Search -- Status Update
• Effect of Priomordial non-Gaussianities on Galaxy Clusters Scaling Relations
• Mean maps for cosmic web structures in cosmological initial conditions
• Normalization of the Matter Power Spectrum via the Ellipticity Function of Giant Galaxy Voids from SDSS DR5
• The Extended Zel'dovich Mass Functions of Clusters and Isolated Clusters in the Presence of Primordial Non-Gaussianity