Non-linear evolution of density fluctuations in numerical cosmology

数值宇宙学中密度涨落的非线性演化

• 批准号: 23740186
• 负责人: HIRAMATSU Takashi
• 金额: $ 2.25万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2013
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23740186/
• 关键词: 宇宙論; 密度揺らぎ; 宇宙論的位相欠陥; 宇宙論的摂動論; 宇宙紐; 修正重力理論; 数値宇宙論; インフレーション; ダークエネルギー; 宇宙論; 密度揺らぎ; 宇宙論的位相欠陥; 宇宙論的摂動論; 宇宙紐; 修正重力理論; 数値宇宙論; インフレーション; ダークエネルギー

As a first step of establishing the foundations of Numerical Cosmology, we developed a general-purpose three-dimensional hyperbolic equation solver for classical field theory, and studied the non-linear evolution of primordial density fluctuations and the topological defects appeared as a result of phase transition of the vacuum states. As for the latter project, we addressed a variety of issues lying across cosmology by virtue of the ubiquitous property of Numerical Cosmology, from the gravitational waves and axions from domain walls, to the dynamical constraints on the model building of supersymmetric models from the colliding meta-stable strings. In addition, we developed a Boltzmann solver for the photons in the early Universe to impose the initial conditions of the density fluctuations. As for the modified gravity theories, we investigated the details of the scalar gravity hidden in the theories, and the possibility of the observational constraints on their theoretical parameters.

作为确定数值宇宙学基础的第一步，我们开发了用于经典田间理论的通用三维双曲方程求解器，并研究了原始密度波动的非线性演化，并且拓扑缺陷似乎是真空态相变的结果。至于后一个项目，我们通过数值宇宙学的普遍特性，从域壁的引力波和轴线到对碰撞元稳定的稳定稳定的稳态模型的模型构建的动力约束，解决了各种问题。此外，我们为早期宇宙中的光子开发了一个玻尔兹曼求解器，以施加密度波动的初始条件。至于修饰的重力理论，我们研究了隐藏在理论中的标量重力的细节，以及对其理论参数的观察性约束的可能性。