Statistical analysis of the large-scale structure of the Universe using observational data and numerical modeling

The statistical properties of elements of the large-scale structure of the Universe are studied using the SDSS DR7 galaxy catalog and a dark-matter halo catalog obtained via numerical modeling using MultiDark Run1. The minimum spanning tree technique is used to distinguish the large-scale structure, and the Core Sampling method is used to analyze its properties. As a result, the SDSS DR7 and MultiDark Run1 catalogs are divided into subcatalogs of two-dimensonal walls and one-dimensional filaments. Some statistical properties of these subcatalogs are compared with theoretical predictions. The mean separation between the walls is measured using both the observations and numerical modeling results (50–60 Mpc/h) and the distribution of the wall surface density is derived. The fraction of the SDSS DR7 galaxy clusters thought to have been distorted by the observational effect called “fingers of God” is estimated. Dense clusters for which this effect is most appreciable constitute ∼15% of the analyzed clusters. The influence of these clusters on the final result is eliminated by fitting the orientation of test cylinders in the Core Sampling method.