Cardassian Model Of The Universe And A Number Of Studies

In the master dissertation, We study the relation between the Cardassian model which modified the Friedmann equation and the accelerated expansion of the universe. We analyze the dynamical character of the Cardassian model with double exponential potentials. Some Subjects will be discussed in the paper:1. Introduction to modern Observations in the Cosmology.2. A briefly review of some kinds of dark energy.3. Analyzing the dynamical character of the Cardassian model.4. Discussing the problem happened in the model.Finally, we found that the Cardassian without dark energy will affect our universe by the double exponential potentials. Each of them control the different epochs in our universe. One is correspond to the Big Bang and the other cause the accelerated expansion of the universe at later time. Although, Cardassian model succeed in illustrating the the accelerated expansion of the universe, but some researches found that this model is failed in small scale.