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

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.

作为建立数值宇宙学基础的第一步，我们发展了一个通用的三维经典场论双曲方程求解器，并研究了真空态相变引起的原初密度涨落和拓扑缺陷的非线性演化.至于后一个项目，我们解决了各种各样的问题，躺在宇宙学的数值宇宙学的无处不在的属性，从引力波和轴子域壁，从碰撞亚稳态弦的超对称模型的模型建立的动力学约束。此外，我们开发了一个玻尔兹曼求解器的光子在早期宇宙中施加的初始条件的密度波动。对于修正的引力理论，我们研究了隐藏在理论中的标量引力的细节，以及观测约束对其理论参数的可能性。

项目成果

A head-on approarch for structure formation

结构形成的正面方法

• 发表时间: 2011
• 作者: Tatsuo Azeyanagi;Noriaki Ogawa and Seiji Terashima;平松尚志
• 通讯作者: 平松尚志

On the Vainshtein mechanism for two body system in DGP model

论DGP模型中二体系统的Vainshtein机制

• 发表时间: 2011
• 作者: 平松尚志;Wayne Hu;小山和哉;Fabian Schmidt
• 通讯作者: Fabian Schmidt

Type-I Cosmic String Network -- network density --

I型宇宙弦网络——网络密度——

• 作者: T.Azeyanagi;T.Kobayashi;A.Ogasahara;K.Yoshioka;Tsutomu Fukuda;K. Morishima;平松尚志
• 通讯作者: 平松尚志

Bound states of Type-I cosmic strings

I 型宇宙弦的束缚态

• 发表时间: 2014
• 作者: 平松尚志;山内大介
• 通讯作者: 山内大介

Bound states of extreme Type-I cosmic strings in two-dimensional space

二维空间中极端I型宇宙弦的束缚态

• 发表时间: 2013
• 作者: 平松尚志;山内大介
• 通讯作者: 山内大介