Nonlinear growth of density fluctuations in the 3-dimensional self-gravitating systems

三维自引力系统中密度涨落的非线性增长

• 批准号: 62460039
• 负责人: SATO Humitaka
• 金额: $ 3.97万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-62460039/
• 关键词: density fluctuation; galaxy formation; instability; general relativity; gramitational wave; pulsar; supnernova; nonlinear system; インフレーション宇宙; 重力不安定; 非線型過程; 宇宙の大局構造; 星形成; 自己重力系; 超新星爆発; 中性子星

Structure formations in the hierarchy of the universe are all related with the nonlinear growth of density fluctuations in the 3-dimensional self-gravitating system. In this research project, the characteristics of gravity in the structure formation was studied numerically as well as analytically. The subject is classified to the following three:1. Cloud and Stars Stability and fragmentation of an isothermal cloud was analyzed extensively by the 3-dimensional simulation code and the linear theory. Angular momentum transportation in the toras was analyzed by the quasi-nonlinear method. Effect of magnetic field in the evolution of cloud was systematically analyzed.2. Collapse and Supernova The code to compute the 3-dimensional gravitational collapse has been developed. Gravitational waves emission in the process of nertron stars coalescence was firstly computed by the post Newtonian approximation and the wave form was extensively studied. Supernova explosion was firstly computed by the 3-dimensional code and suggested the formation of clumpiness in the ejects. Propagation of X and gamma ray in the supernova ejecta was also studied.3. Cosmology Dynamical feature of 1-dimensional sheetlike self-gravitating system was studied in relation to the catastrophy theory. Various problems of cosmology were also studied.

宇宙层次结构的形成都与三维自引力系统中密度涨落的非线性增长有关。在本研究项目中，对构造地层中的重力特征进行了数值和解析研究。本课题分为以下三个方面：1。利用三维模拟程序和线性理论对等温云的稳定性和破碎性进行了广泛的分析。用拟非线性方法分析了环体中的角动量输运。系统地分析了磁场对云团演化的影响。坍缩和超新星已经开发了计算三维引力坍缩的代码。首先用后牛顿近似计算了中子星合并过程中引力波的发射，并对其波形进行了广泛的研究。首先用三维代码计算了超新星爆炸，并提出了在弹射物中团块的形成。研究了X射线和伽马射线在超新星喷发物中的传播。从灾变理论的角度研究了一维片状自引力系统的动力学特性。还研究了宇宙学的各种问题。

项目成果

Y.Suto: "Microwave Background Anisotropies and the Primordial Spectrum of Cosmological Density Fluctuations" Astrophys.J.(in press).

Y.Suto：“微波背景各向异性和宇宙密度涨落的原始光谱”Astrophys.J.（出版中）。

T.Nakano: "Magnetic braking of the rotation of molecularc cloud cores" Mon.Not.R.astr.Soc.241(1989)241(1989)495-505.

T.Nakano：“分子云核心旋转的磁制动”Mon.Not.R.astr.Soc.241(1989)241(1989)495-505。

N.Gouda: "Evolution of Perturbations in a Baryon-Dominated Universe:Gauge-Invariant Analysis" Astrophys.J.341(1989)557-574.

N.Gouda：“重子主导宇宙中的扰动演化：规范不变分析”Astrophys.J.341(1989)557-574。

H.Kubotani: "The Surface Wave Instability of Stratifie k Incommpressible Cylinders with Differential Rotation" Prog.Theor.Phys.82. 523-534 (1989)

H.Kubotani：“具有差动旋转的分层不可压缩圆柱体的表面波不稳定性”Prog.Theor.Phys.82。

S.Tadaki: "Cosmological Domain Walls Coupled to Gravity" Phys.Rev.D(in press).

S.Tadaki：“与重力耦合的宇宙域壁”Phys.Rev.D（正在出版）。