Large Scale Structure
  Catalogues of galaxies, clusters of galaxies and superclusters - sources of information to study the large-scale structure of the Universe are reviewed. The power spectrum of density perturbations, and the correlation function are discussed as principal description functions which characterize the large-scale structure. Special attention is payd to the geometric interpretation of these functions, i.e. the way in which the various properties of the distribution of galaxies in systems and systems themselves are reflected in these functions. We discuss cosmological parameters which characterize general properties of the Universe: the Hubble constant, densities of various populations of the Universe, and parameters of the power spectrum of galaxies and matter. 
Jaan Einasto