Jeans instability and anti-screening in gravitational-antigravitational model of Universe

The hypothesis of antigravitational interaction of elementary particles and antiparticles is considered on the basis of the simple two-component hydrodynamic model with gravitational repulsion and attraction. It is shown increasing of the Jeans instability rate, the presence of antiscreening and the dominative role of the gravitational repulsion as a possible mechanism for spatial separation of matter and antimatter in Universe, as well as the observable acceleration of the far galaxies. The sound wave is found for the two-component gravitational-antigravitational system, which starts for k = 0 in the case of annihilation neglecting. The suggested approach permits to reestablish the idea about baryon symmetry of Universe, causing its steady flatness of the large scale and accelerated Universe expansion.