暗能量及其热力学性质的研究

发布时间：2019-06-09 14:05

【摘要】：宇宙的加速膨胀是当代宇宙学的一个基本事实,它得到了来自Ia型超新星、宇宙微波背景辐射和基隆数字天宇测量以及宇宙大尺度等众多观测数据的证实,同时也成为宇宙学研究的一个重点和热点。对于当今宇宙加速膨胀的现象,一个得到普遍认同的解释是宇宙中均匀分布着一种称之为暗能量的特殊物质,它具有负压强,正是这种负压强推动了宇宙的加速膨胀。此外,也有修正的引力理论和额外维理论解释宇宙加速膨胀。本文首先介绍了宇宙学的相关基础知识(第二章),内容包括宇宙学原理、标准宇宙学模型和暴涨宇宙学模型以及解释宇宙加速膨胀的几种常见暗能量模型和修正的引力理论。接着介绍了我们的主要研究工作(第三章到第五章)。首先我们研究了修正可变Chaplygin Gas模型以及相互作用的修正可变Chaplygin Gas模型的演化行为(第三章)。具体分析了模型中宇宙学参量：暗能量状态参量wde、各物质能量密度比Ωi以及减速因子q。此外,鉴于增长指标f与哈勃参数H(z)的结合可以提供探索暗能量的性质以及宇宙结构形成的重要信息,我们还讨论了修正可变Chaplygin Gas模型中增长指标f的演化特性。最后,介绍了甄别暗能量模型的Statefinder参数诊断法,并利月(?)Statefinder参数对相互作用的VMCG模型进行了诊断。另一方面,宇宙在局域平衡下可以看作一个大的热力学系统,我们从热力学角度研究和探讨了暗能量的性质(第五章)。具体地,在参数化暗能量模型w=wo+w1(?),探讨表观视界和事件视界包络的宇宙中广义热力学定律是否成立；此外我们采用Markov Chain Monte Carlo方法,利用当前天文观测数据：SNIa超新星,重子声速振荡(BAO),观测的哈勃数据(OHD)以及宇宙微波背景辐射(CMB)限制了修正可变Chaplygin Gas模型的参数(第四章)。并利用这些限制参数值,探讨修正可变Chaplygin Gas模型中,表观视界、事件视界以及粒子视界包络的宇宙的广义热力学性质(第五章)。最后我们给出本论文的结论与展望部分。
[Abstract]:The accelerated expansion of the universe is a basic fact of contemporary cosmology, which has been confirmed by many observational data, such as Ia supernova, cosmic microwave background radiation, Keelung digital celestial measurement, cosmic large scale and so on. At the same time, it has also become a focus and hot spot of cosmology. For the phenomenon of accelerated expansion of the universe, a widely accepted explanation is that there is a uniform distribution of a special material called dark energy in the universe, which has a strong negative pressure, which promotes the accelerated expansion of the universe. In addition, there are also modified gravity theory and extra dimension theory to explain the accelerated expansion of the universe. In this paper, the basic knowledge of cosmology is introduced (chapter 2), including cosmological principles, standard cosmological models and inflationary cosmological models, as well as several common dark energy models and modified gravitational theories that explain the accelerated expansion of the universe. Then it introduces our main research work (chapters III to V). Firstly, we study the evolution behavior of modified variable Chaplygin Gas model and interaction modified variable Chaplygin Gas model (Chapter 3). The cosmological parameters in the model, the dark energy state parameter wde, the energy density ratio of each material and the deceleration factor Q, are analyzed in detail. In addition, since the combination of growth index f and Hubble parameter H (z) can provide important information to explore the properties of dark energy and the formation of cosmic structure, we also discuss the evolution characteristics of growth index f in modified variable Chaplygin Gas model. Finally, the Statefinder parameter diagnosis method for discriminating dark energy model is introduced, and the interaction VMCG model is diagnosed by Liyue (?) Statefinder parameter. On the other hand, the universe can be regarded as a large thermodynamic system under the local equilibrium. We study and discuss the properties of dark energy from the thermodynamic point of view (Chapter 5). Specifically, in the parametric dark energy model w=wo w1 (?), whether the generalized thermodynamic law is valid in the universe with apparent horizon and event horizon envelope is discussed. In addition, we use Markov Chain Monte Carlo method, using the current astronomical observation data: SNIa supernova, baryons sound velocity oscillatory (BAO), The observed Hubble data (OHD) and cosmic microwave background radiation (CMB) limit the parameters of the modified variable Chaplygin Gas model (Chapter 4). By using these restricted parameters, the generalized thermodynamic properties of the universe with apparent horizon, event horizon and particle horizon envelope in the modified variable Chaplygin Gas model are discussed (Chapter 5). Finally, we give the conclusion and prospect of this paper.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：P159

【共引文献】