Drans-Dicke理论及其标量场解析势的研究

发布时间：2018-09-09 19:34

【摘要】：近年来，通过1a型超新星，宇宙微波背景辐射各向异性探测器和宇宙大尺度结构等天文观测可知，当前我们的宇宙正在加速膨胀，宇宙为什么加速膨胀的问题，已经成为目前宇宙学研究的热门的话题之一。对于宇宙加速膨胀的现象，其中一个最普遍的解释就是宇宙中含有一种称为暗能量的特殊物质，它具有负的压强，正是这种负压强物质的存在从而推动宇宙的加速膨胀。此外，，还有修正的引力理论解释宇宙的加速膨胀。宇宙的加速膨胀对基于爱因斯坦广义相对论构建的标准宇宙学模型提出了挑战。由此引出的一些广义相对论引力理论的替代者及修改理论被不断的寻找及研究。Brans-Dicke（BD）理论是广义相对论的替代理论之一。BD理论作为标量张量理论，它能在两个标架下表示，分别为Jordan标架和Einstein标架。在Einstein标架下BD标量场不与几何量—Ricci标量R耦合，但是它与物质系统相互作用，这种不规则的耦合在Einstein引力下没有对应，这就暗示了物质和标量场的能量动量张量各自不守恒。而Jordan标架下，BD标量场与R耦合。两种标架下的BD理论可通过共形变换相联系。我们在两种标架下，研究了具有BD标量场解析势的宇宙学。结合天文观测给出的参数拟合值，我们讨论了BD标量势的演化以及比较两种标架下BD标量场势能的差别。
[Abstract]:In recent years, through astronomical observations such as Type 1a supernova, cosmic microwave background radiation anisotropy detector and cosmic large-scale structure, we can see that our universe is speeding up expansion, and why is the universe accelerating to expand? It has become one of the hot topics in cosmology research. One of the most common explanations for the accelerating expansion of the universe is that the universe contains a special substance called dark energy, which has a negative pressure, and it is the existence of this negative pressure that promotes the accelerated expansion of the universe. In addition, there is a modified gravitational theory to explain the accelerating expansion of the universe. The accelerating expansion of the universe challenges the standard cosmological model based on Einstein's general relativity. The substitution and modification of some generalized relativistic gravity theories has been continuously searched for and studied. Brans-Dicke (BD) theory is one of the substitution theories of general relativity. BD theory, as a scalar Zhang Liang theory, can be expressed under two frames. Jordan frame and Einstein frame respectively. Under the Einstein frame, the BD scalar field is not coupled with the geometric quantity -Ricci scalar R, but it interacts with the material system. This irregular coupling does not correspond to the Einstein gravity, which implies that the energy and momentum Zhang Liang of the mass and scalar field are not conserved. Under the Jordan frame, the BD scalar field is coupled with R. The BD theory under two frames can be related by conformal transformation. We have studied cosmology with analytical potential of BD scalar field under two frames. The evolution of BD scalar potential and the difference of potential energy of BD scalar field under two frames are discussed based on the parameter fitting values obtained from astronomical observations.
【学位授予单位】：辽宁师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P159

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