Structure of cosmic web in non-linear regime: the nearest neighbour and spherical contact distributions

Abstract

In non-linear scales, the matter density distribution is not Gaussian. Consequently, the widely used two-point correlation function is not adequate anymore to capture the matter density field's entire behaviour. Among all statistics beyond correlation functions, the spherical contact (or equivalently void function), and nearest neighbour distribution function seem promising tools to probe matter distribution in non-linear regime. In this work, we use halos from cosmological N-body simulations, galaxy groups from the volume-limited galaxy group and central galaxies from mock galaxy catalogues, to compare the spherical contact with the nearest neighbour distribution functions. We also calculate the J-function (or equivalently the first conditional correlation function), for different samples. Moreover, we consider the redshift evolution and mass-scale dependence of statistics in the simulations and dependence on the magnitude of volume-limited samples in group catalogues as well as the mock central galaxies. The shape of the spherical contact probability distribution function is nearly skew-normal, with skewness and kurtosis being approximately 0.5 and 3, respectively. On the other hand, the nearest neighbour probability distribution function is nearly log-normal, with logarithmic skewness and kurtosis being approximately 0.1 and 2.5, respectively. Accordingly, the spherical contact distribution function probes larger scales compared to the nearest neighbour distribution function, which is influenced by details of structures. We also find a linear relation between the mean and variance of the spherical contact probability distribution function in simulations and mock galaxies, which could be used as a distinguishing probe of cosmological models.

20 pages, 12 figures, 11 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (16)

• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• Cosmology and the Bispectrum
• Dark matters on the scale of galaxies
• Cosmological cross-correlations and nearest neighbor distributions
• Perturbation theory and excursion set estimates of the probability distribution function of dark matter, and a method for reconstructing the initial distribution function
• Probing Galaxy Assembly Bias in BOSS Galaxies Using Void Probabilities
• Mapping the real space distributions of galaxies in SDSS DR7: I. Two Point Correlation Functions
• Galaxy Bias and ${\sigma }_8$ from Counts in Cells from the SDSS Main Sample
• Using the Topology of Large Scale Structure to constrain Dark Energy
• New fitting formula for cosmic non-linear density distribution
• Multi-wavelength mock galaxy catalogs of the low-redshift Universe
• Late time sky as a probe of steps and oscillations in primordial Universe
• Genus Topology and Cross-Correlation of BICEP2 and Planck 353 GHz B-Modes: Further Evidence Favoring Gravity Wave Detection
• Cosmological Parameter Estimation Using the Genus Amplitude - Application to Mock Galaxy Catalogs
• Evolution of skewness and kurtosis of cosmic density fields
• The position-dependent matter density probability distribution function