Two-dimensional simulation of the gravitational system dynamics and formation of the large-scale structure of the universe

The problems of small, long-wave perturbations evolving at a nonlinear stage under the effect of gravitational forces in the expanding universe are analyzed. Results of numerical calculations show that in the case of collisionless particles, as well as in the gas-dynamic case, the cellular structure appeared at the nonlinear stage in the case of the adiabatic perturbations. In a Robertson-Walker universe (Omega equal to 1) the cellular structure exists for a finite time, then fragments into a few compact objects, while in the open universe (Omega less than 1) the cellular structure also exists if the amplitude of initial perturbations is large enough. Formation of the cellular structure depends mainly on the choice of the spectrum of initial perturbations (short waves must be suppressed).