الكون المزدوج الفيزياء الفلكية والكونيات

twin universe astrophysics and cosmology Matter ghost matter astrophysics. 5 : Results of numerical 2d simulations. VLS. About a possible schema for galaxies' formation.(p5)
...Now, dealing with two species (matter plus ghost matter), if Vthr << V th cr we get two clumps, whose distance corresponds to antipodality and maximum distance between them. See figure 14.

** ** Fig. 14 :** Schematic result of joint gravitational instability** **matter plus ghost matter, when **Vthr << Vth cr (initially cold medium)

...If Vthr >> Vth cr the system remains uniform and the two species closely mixed. For Vthr » Vth cr we get long duration emulsion-like patterns, see figure 15 (this result was presented in a former paper [1].

Fig. 15 : Emulsion pattern for Vth = Vth cr

...We have used two sets of interacting 5000 mass-points. As we can see the result is similar to the one of figure 11 bis . The same method could be extended to 3d system (which is far beyond the possibilities of our system). Although 3d systems are different from 2d systems we can expect 3d simulations would provide similar long duration 3d emulsions. The join instabilities theory (coupled Jeans equations) is presented in section 11.

3. The problem of the very large structure of the Universe

...We take initial condition with uniform mass distributions for normal matter (t hat we call simply matter) and ghost matter. r being the mass density of the matter and r* the mass-distribution of the ghost matter, we choose for initial conditions ro* = 64 ro. At this level, just see what happens. We have performed 2d numerical simulations with two sets of 5000 mass-points, that are supposed to represents some clusters of matter and ghost matter, with masses M and M*, which means that M* = 64 M. We give these two sets maxwellian distributions of 2d thermal velocities with <V*> = 4 < V > . We neglect the expansion phenomena (it would be very difficult to deal with, for we do not know how to describe gravitational force in an expanding universe). The results are the following. The more massive population, the ghost matter'one, whose Jeans time is eight times shorter than the other one’s runs the game and forms clumps, through gravitational instability, that repel and confines the other population in the remnant place. We get a 2d-cellular structure. The characteristic birth time of the whole structure is close to the Jeans time of the heavier population, of the ghost matter.

. Fig. 16 :** Results of simulations performed by F.Lansheat.** Left : ghost matter clumps. Right : matter structure. . Fig. 17 : Superposition of the two. ...The general pattern depends on the initial conditions. In a former paper [6] bigger clumps of ghost matter were obtained, with a more regular cellular structure for normal matter, due to the choice of a higher initial ghost matter temperature. This approach, aiming at a modelization of the very large scale structure of the Universe, is fundamentally different from the classical approaches based on the dark matter. In classical matter-dark matter systems, stability is problematic : gravitational instability, by rising up the density locally, increases the thermal velocities and makes the observed structures to disappear in time. The system with two repelling populations is qualitatively different, each population creating a potential barrier for the other one. This explains the great stability in time and space : the cells of matter keep the clumps of ghost matter in place, and vice-versa.