Regularity of the large-scale structure of the Universe

Recent analysis of the distribution of clusters of galaxies is reviewed. Clusters of galaxies located in rich superclusters form a quasiregular lattice. The mean power spectrum of galaxies and clusters has been found, it has a peak at wavelength ${\lambda }_0=120$~\Mpc corresponding to the lattice step. The power spectrum of galaxies is reduced to that of matter. The empirical power spectrum is compared with theoretical spectra for mixed dark matter models, and primordial power spectra are calculated. The primordial power spectrum has a peak which may be due to processes during the inflationary stage of the structure evolution.