The Analysis of the Gravitational Growth of the Matter, Thermal Evolution and the CMB anisotropies, which are related to the Large-Scale Structures Formations.

与大规模结构形成相关的物质引力增长、热演化和宇宙微波背景各向异性分析。

• 批准号: 06640352
• 负责人: GOUDA Naoteru
• 金额: $ 1.41万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06640352/
• 关键词: Cosmology; Large-Scale Structures in the Universe; Cosmic Microwave Background; Galaxy Formation; Gravitational Many-body Systems

I analyzed the nonlinear dynamics of the gravitational growth of cosmological density fluctuations and the pattern of clustering which are much related to the large-scale structure and galaxy formations. Furthermore I analyzed the merging history of dark haloes and galactic dynamics which are very important processes in the formations and evolutions of the galaxies. I got the following results by these analysis ;1) I got the law of nonlinear Fourier-mode coupling in the nonlinear growth of density fluctuations by the pseudo-spectral method.2) I showed that the power index of the power spectrum of density fluctuations is determined only by the type of singularity which is classified in accord with the catastrophe theory in both two-dimensional and three-dimensional systems. Furthermore we found the relation between the power index of the two-point correlation function and other quantities in the strongly nonlinear regime by the analysis of scale-invariant solutions of the BBGKY equation.3) We found the time scale of the relaxation to the quasi-equilibrium state in the one-dimensional self-gravitating many-body systems. Furthermore we showed that there are many quasi-equilibrium states and the system wanders between the states. The distribution of time scale of transition is found to obey the power law. We believe that this is resulted from the fact that partial space which corresponds to a quasi-equilibrium state distributes in the fractal form in the whole phase space.4) We clarified the limitations of the Press-Schechter formalism which is often used for estimate of the mass functions of dark haloes. Furthermore we showed that it is very important to consider the effect of spatial correlation in analyzing the merging history of dark haloes.5) We estimated the difference between the Hubble constant observed in the local universe and the global Hubble constant by taking into account the bulk flows of galaxies.

分析了宇宙密度涨落引力增长和星系团模式的非线性动力学，它们与大尺度结构和星系形成密切相关。此外，我还分析了暗晕和星系动力学的合并历史，它们是星系形成和演化中非常重要的过程。通过这些分析，我得到了以下结果：1)用伪谱方法得到了密度涨落的非线性增长中的非线性傅里叶模耦合定律。2)我证明了密度涨落功率谱的幂指数只由奇点的类型决定，这在二维和三维系统中都符合突变理论。通过对BBGKY方程的标度不变解的分析，得到了强非线性区域中两点关联函数的幂指数与其他量之间的关系。3)找到了一维自引力多体系统准平衡态的驰豫时间尺度。此外，我们还证明了存在许多准平衡态，并且系统在这些态之间游走。研究发现，过渡时间尺度的分布服从幂规律。我们认为这是因为对应于准平衡态的部分空间在整个相空间中以分形态的形式分布。4)我们澄清了经常用于估计暗晕质量函数的Press-Scheck hter公式的局限性。此外，我们还指出，在分析暗晕合并历史时，考虑空间相关性的影响是非常重要的。5)我们通过考虑星系的整体流动，估计了在局部宇宙中观测到的哈勃常数与全球哈勃常数之间的差异。

项目成果

Toshio Tsuchiya: "Relaxation Processes in One-Dimentional Self-Gravitating Many-Body Systems" Physical Review E. 53. 2210-2216 (1996)

Toshio Tsuchiya：“一维自引力多体系统中的松弛过程”物理评论 E. 53. 2210-2216 (1996)

Naoteru Gouda: "Reconstruction of Initial Cosmological Density Flnctuations and Analys's of Non-linear Dynamics of Denslty Fluctuations by the Pseudo-Spectral Method" Proceedings of IAU Symposium No.168. (印刷中). (1995)

Naoteru Gouda：“用伪谱方法重建初始宇宙学密度波动和密度波动非线性动力学分析”IAU 研讨会第 168 号会议记录（1995 年）。

Taihei Yano: "Limitations of the Press-Schechter Formalism" The Astrophysical Journal. 466(印刷中). (1996)

Taihei Yano：“新闻的局限性 - 谢克特形式主义”《天体物理学杂志》466（出版中）。

Naoteru Gouda: "Reconstruction of Initial Cosmological Density Fluctuations by the Pseudo Spectral Method" The Astrophysical Journal. 436. 542-546 (1994)

Naoteru Gouda：“用伪光谱方法重建初始宇宙密度涨落”《天体物理学杂志》。

Naoteru Gouda: "Non-Linear Growth of Two-Dimensional Cosmological Density Flutuations and Type of Singularity in Accord with the Catastrophe Theory" The Astrophysical Journal. 469. 455-469 (1996)

Naoteru Gouda：“符合突变理论的二维宇宙密度涨落的非线性增长和奇点类型”《天体物理学杂志》。