| Nowadays,human beings have entered into an era of precise cosmology.Resent years, ob-servations of type Ia super-novae, accurate date on the cosmic microwave background and large-scale structure analysis showed that our universe is at the stage of accelerating. The discoveryof accelerating expansion of the universe imposes a great new challenge to the modern theory ofphysics and entrust a new mission to the scientific computation. How to explain the acceleratedexpansion of the universe become one of the popular questions. People have proposed manykinds of theories and cosmological models to explain the acceleration. Therefore the currentwork studies a kind of Cardassian model which is the viscous Cardassian PL model in a non-flatuniverse by the numerical computation method.This paper first introduces the background knowledge of modern cosmology, includingfundamental theory, standard cosmological model and inflation in the early universe. After that,this paper researchs the influence of viscosity for the evolution of the universe and introducesthe viscosity, which can be used as one of the candidates for cosmology difficult. Thus, it can beapplied to the modern cosmological fields. We mainly apply it for the Cardassian PL model ina non-flat universe. This master dissertation will further investigate the viscous Cardassian PLmodel in a non-flat universe and discuss the evolutions of some related cosmological quantities.From the density parameter and equation of state, we can see that our discussions without lossof generality. Furthermore, by applying geometrical diagnostic approaches, i.e., the statefinderto the new model, this paper plots the evolutionary trajectories of the statefinder in r-s plane.It has shown that the viscosity plays very an important role in the Cardassian PL model andimpacts the evolutionary of the universe immediately. |
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