关于广义Hobbit模型的理论研究

发布时间：2019-05-27 01:57

【摘要】：目前,通过对大量天文观测数据(Ia型超新星、WMAP)进行分析研究,人们逐渐发现原来我们赖以生存的宇宙并不是按照热大爆炸宇宙学模型所描述的那样在进行减速膨胀,而是出人意料的正在加速膨胀中。前不久佩尔马特等三名物理学家也正因超新星的研究而获得了2011年的诺贝尔物理学奖。那么给出宇宙加速膨胀的合理解释也就势在必行.所以人们就对热大爆炸宇宙学模型进行了修正.其中最主要的修正方法有两种,一种是暗能量理论。即假定有一种新的物质成分存在于宇宙中,它的压强为负且均匀分布于大尺度结构中,致使引力效应被它所提供的排斥作用所抵消,因此使宇宙发生了加速膨胀,我们将这种物质命名为暗能量。第二种是修正的Einstein引力场方程的左边也就是时空几何部分,我们称它为引力修正理论。近来,V.F.Cardone等人利用现象学统一模型来解释宇宙加速膨胀时提出了一种现象学模型,即所谓的Hobbit模型.之后此模型得到了进一步拓展,使其可以描述包括暴胀在内的宇宙四个演化阶段,即广义的Hobbit模型,该模型在以物质为主导之后的漫长时间内的演化类似于ACDM模型.本文对其在相互作用的情况下分别进行了两个方面的讨论。一是广义的Hobbit模型作为一个暗能量模型,其暗能量对结构形成的影响.二是当广义的Hobbit模型作为一个自治系统,讨论模型本身的稳定性问题.结果表明就结构形成方面而言此模型是与ACDM模型和观测事实相符合的,但是在稳定性方面的讨论中我们却发现其不能很好的反映我们真实的宇宙.这样我们也就可以看出与正压背景流体相互作用的广义Hobbit模型并不是一个理想的模型。
[Abstract]:At present, through the analysis and study of a large number of astronomical observation data (IA supernova, WMAP), it is gradually discovered that the universe on which we depend is not slowing down and expanding as described in the thermal Big Bang cosmological model. Instead, it is unexpectedly accelerating expansion. Three physicists, including Permatt, also won the 2011 Nobel Prize in physics for supernova research. Then it is imperative to give a reasonable explanation for the accelerated expansion of the universe. So the cosmological model of the thermal Big Bang has been modified. There are two main correction methods, one is dark energy theory. That is to say, assuming that there is a new material composition in the universe, its pressure is negative and evenly distributed in large-scale structures, resulting in the gravitational effect being offset by the rejection it provides, thus accelerating the expansion of the universe. We name this substance dark energy. The second is the left side of the modified Einstein gravitational field equation, which is the geometric part of time and space, which we call the gravitational correction theory. Recently, when V.F.Cardone et al used the unified phenomenological model to explain the accelerated expansion of the universe, he proposed a phenomenological model, the so-called Hobbit model. After that, the model is further extended so that it can describe the four evolution stages of the universe, namely, the generalized Hobbit model, which is similar to the ACDM model in the long time after it is dominated by matter. In this paper, we discuss it in two aspects under the condition of interaction. First, as a dark energy model, the generalized Hobbit model has the influence of dark energy on the formation of the structure. Second, when the generalized Hobbit model is an autonomous system, the stability of the model itself is discussed. The results show that the model is consistent with the ACDM model and the observed facts in terms of structure formation, but in the discussion of stability, we find that it can not reflect our real universe very well. In this way, we can see that the generalized Hobbit model interacting with barotropic background fluid is not an ideal model.
【学位授予单位】：辽宁师范大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：P159

【共引文献】