在一类矢量-张量宇宙学模型中的动力学分析

研究了一类矢量-张量宇宙学模型中的动力学行为.给出了这类矢量-张量宇宙学模型的所有临界点和相应的参数条件,通过线性近似的方法得到了临界点的性质,利用nullcline技术和数值计算得到这类矢量-张量宇宙模型动力学系统的整体行为,分析得出了宇宙可以从物质优势演化到矢量优势的参数区间,最后,考察了宇宙加速膨胀的条件,发现在这一类矢量-张量宇宙模型中,宇宙后期的加速只有当宇宙演化为矢量优势的情形时才会发生.

Dynamical behavior of the universe in a vector-tensor Gravity

In this paper, we will study the local and global dynamical behavior of the universe in some vector-tensor theories of gravity. We gave out all critical points and their parameters conditions, and the behavior of solutions near the critical points are presented. We used the qualitative technique of nullcline to study the global behavior of the system, and gave out the theory pa- rameters domains in which the universe could evolve from matter domination to vector domination. A most interesting and important conclusion we reached is that the universe evolves with an late-time acceleration in the vector domination in those vector-tensor theories of gravity.