Non-linear Cosmic Perturbation Equations

In the standard model of big bang cosmology, the universe homogeneous and isotropic space is a prerequisite for research. With the rapid development of space technology, human exploration of the universe has reached unprecedented levels. To the Hubble Space Telescope, COBE satellite, WMAP satellite, represented by the launch of a new generation of detectors, so that the first human to accurately detect the depths of the universe, in particular the 2006 Nobel Prize in Physics in recognition of the cosmic microwave background radiation blackbody spectrum and anisotropy of the probe, marked the era of precision cosmology has arrived.Further observations showed that the space homogeneous and isotropic universe is only greater than 70-100 Mpc scale in the observation of the establishment of similar circumstances, so examine the uneven and anisotropy of the universe (that the universe perturbation) on the evolution of the universe further research on the impact of a real universe is a necessary step. Perturbation of the universe has become the cornerstone of the early evolution of the universe.As the era of precision cosmology, and accuracy is beyond the linear terms, so the nonlinear term on the impact of cosmic evolution becomes more and more attention. For the non-linear perturbation theory of the universe, has more significance.From the general theory of relativity in the law of conservation of energy momentum tensor of the starting, not limited to the specific coordinate system, through the role of the perturbation operator, calculated by a linear perturbation equation of the universe, it in large scale under the adiabatic perturbation non-linear conservation law is consistent perturbative generalization, and finally we have obtained its second-order perturbation.