The Research On New Generalized Chaplygin Gas Model And Its Relative Problems

With Ia supernovae, cosmic microwave background radiation and large-scalestructure and other observations show that our universe is accelerating expansionin the current state. Astronomical observations also show that the universe isroughly the proportion of each component: 73% of dark energy, 23% of the darkmatter and 4% for baryonic matter. A large proportion of dark energy is an importantpart of the current universe. For more scientific study of the universe, peoplebuild a large number of cosmological model, The simplest dark energy model isa cosmological constant. Dark energy model is also common: Quitessence, Phantom,Tachyon, K-essence, the holographic dark energy, Chaplygin gas (CG) andits extension model.For the CG and its promotion model, the most attractive is the nature of theuniverse can unified the dark two parts (dark matter and dark energy) which isnot visible. The most widely used is the generalized Chaplygin gas (GCG) model.The new generalized Chaplygin gas (NGCG) model as a promotion model forthe GCG model has also been established. The model contains that dark energyparameters is constant. The early behavior is similar to dark matter, but latersimilar to the cosmological constant.In this paper, it will discuss the the stability of dynamical systems in theinteraction between a barotropic perfect fluid and NGCG fluid. Interaction termis taken as Q = 3Hc(ρ_NGCG+ρ_γ)). Through the autonomous system of NGCG, itcan obtain the critical points, and then know the attractor of this model. Furthermore,the evolutionary curves of the state parameter, the density parameters aswell as the sound speed in NGCG model are plotted, which illustrate the stabilityof NGCG model. Finally, it performs the Om diagnostic in order to distinguishbetween the different NGCG andΛCDM.