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Evolution of Inflationary Universe in Extended Gravitational Theories

扩展引力理论中暴胀宇宙的演化

基本信息

批准号：
03640345
负责人：
SATO Katsuhiko
金额：
$ 1.47万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03640345/
关键词：
Cosmology Inflation Phase Trandition Early Universe インフレ-ション真空の相転移

项目摘要

Inflationary Universe model, which was proposed by A. Guth and present researcher independently, is a standard scenario of early universe. This is recognized not only as a consequence of unified theories of elementary interaction, but as an essential step of the creation of universe. This model is also supported by observations. Recently COBE (Cosmic background explorer) discovered the fluctuation of background radiation, and found that the spectrum of the fluctuations is very consistent with the prediction of Inflationary model.In spite of the success of this model, there is a severe problem whether any inhomogeneous and anisotropic universe can evolve to homogeneous and isotropic universe or not. In this research, we investigated this problem called "Cosmic No-hair Conjecture" by using new formalism of the calculation of general relativity, Regge Calculus. For the homogeneous and anisotropic universe, we found the constraint for the initial condition which evolve to inflationary universe not only for usual exponential expanding universe model, but also for the power law expanding models. However, there still remains problem that Hamiltonian constraint is inconsistent with evolution equations for inhomogeneous models.We also investigated formation of topological defects in early universe during phase transition, and showed that "texture" give a consistent density fluctuation for structure formation in the Big Bang Model,in particular, the deviation from Gaussian helps the formation of large scale structure.

膨胀宇宙模型是由A.Guth和现在的研究者独立提出的，是早期宇宙的标准情景。这不仅被认为是基本相互作用统一理论的结果，而且被认为是创造宇宙的必要步骤。这一模型也得到了观测结果的支持。最近，COBE(宇宙背景探测器)发现了背景辐射的涨落，并发现涨落的频谱与膨胀模型的预测非常一致。尽管该模型取得了成功，但任何非均匀和各向异性的宇宙是否能演化为均匀和各向同性的宇宙，仍然是一个严重的问题。在这项研究中，我们利用广义相对论计算的新形式--Regge演算，研究了“宇宙无毛猜想”这个问题。对于均匀各向异性宇宙，我们不仅找到了通常的指数扩展宇宙模型的初始条件演化为膨胀宇宙的约束条件，而且找到了幂定律扩展模型的初始条件的约束条件。我们还研究了早期宇宙相变过程中拓扑缺陷的形成，发现在大爆炸模型中，“织构”给出了结构形成的一致密度涨落，特别是偏离高斯分布有助于大尺度结构的形成。