Cosmological observations in the inhomogeneous Universe and the evolution of a local inhomo geneity

非均匀宇宙中的宇宙学观测和局部非同质基因的演化

• 批准号: 10640266
• 负责人: TOMITA Kenji
• 金额: $ 2.11万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640266/
• 关键词: cosmology; gravitation; inhomogeneity; Hubble const; Void; gravitational lens; cosmological constant; bulk flow; void; cosmology; relativity; inhomogeneitv; CMB; anisatropy

Parameters characterizing homogeneous and isotropic cosmological models (Hubble constant HィイD20ィエD2 and deceleration parameter, and so on) are determined on the basis of statistical analyses for the spatial distribution and velocities of astronomical objects. The values of Hubble constant are scattered even at present, and there is a tendency that HィイD20ィエD2 【approximately equal】 72km sィイD1-1ィエD1 and MpcィイD1-1ィエD1 in the range within 100 Mpc and HィイD20ィエD2 60 km sィイD1-1ィエD1 and MpcィイD1-1ィエD1 in the range of 100〜400Mpc. According to recent observation due to supernovae of type Ia, moreover, the deceleration parameter is found to be negative (i.e. the acceleration of the Universe).On the other hand, the bulk flow existing within 100 Mpc is not compatible with the homogeneity of cosmological models, which was discovered by Hudson et al. (1999) and Willick (1999). If we assume the existence of this bulk flow, a possible way is to consider an inhomogeneous cosmological (void) model in order to make the theory and observation compatible. This model consists of the outer region with high-density and smaller Hubble constant and the inner (void) spherical region with low-density and larger Hubble constant, and our observer (O) is assumed to be in a position deviated from the center (C). This local void-like region plays an important role similar to the cosmological constant.In the present project, we treated (1) an inhomogeneous cosmological model with the above two regions to investigate the observational aspects of inhomogeneous models, and (2) numerical simulations of gravitational lensing the null-geodesic equation, in order to study the cosmological parameters in inhomogeneous models. Due to these works we have found the consistency between above various observations and theoretical models, and fruitful possibilities of inhomogeneous models.

表征均匀各向同性宇宙学模型的参数（哈勃常数HighD20和减速参数等）是在对天体空间分布和速度的统计分析的基础上确定的，即使目前哈勃常数的值也是分散的，并且有HiiD20ieD2【约等于】72km的趋势D1-1D1 和 D1 在 100 Mpc 范围内，D20D2 在 60 km 范围内 D1-1D1 和 D1- 1D1 在 100〜400Mpc 范围内，根据最近对 Ia 型超新星的观测，发现减速参数为消极的（即宇宙的加速度）。另一方面，Hudson 等人 (1999) 和 Willick (1999) 发现，100 Mpc 内存在的整体流与宇宙学模型的均匀性不相容。假设存在这种整体流，一种可能的方法是考虑非均匀宇宙学（空洞）模型，以使理论和观测相兼容。该模型由外部区域组成。高密度和较小的哈勃常数以及具有低密度和较大哈勃常数的内部（空洞）球形区域，并且我们的观察者（O）被假设处于偏离中心（C）的位置。区域起着类似于宇宙学常数的重要作用。在本项目中，我们处理（1）具有上述两个区域的非齐次宇宙学模型，以研究非齐次模型的观测方面，以及（2）数值通过对零测地线方程进行引力透镜模拟，以研究非齐次模型中的宇宙学参数，通过这些工作，我们发现了上述各种观测结果与理论模型之间的一致性，以及非齐次模型的丰富可能性。

项目成果

M. Yamada, N. Sugiyama, and J. Silk: "On the Effects on the Arisotropy of the CMB by AGN Cocoons"Astrophys. J.. 522. 66-73 (1999)

M. Yamada、N. Sugiyama 和 J. Silk：“论 AGN Cocoons 对 CMB 各向异性的影响”天体物理学。

T.Chiba,N.Sugiyama T.Nakamura: "Observational Tests of X-Matter Models" Month.Not.R.Astron.Soc.310巻1号. 72-80 (1998)

T.Chiba、N.Sugiyama T.Nakamura：“X 物质模型的观察测试”Month.Not.R.Astron.Soc.310，No.1 (1998)。

冨田憲二: "Bulk Flows and CMB Dipole Anisotropy in cosmological Void Models"Astrophys.J.. 529. 26-37 (2000)

Kenji Tomita：“宇宙学空洞模型中的体流和 CMB 偶极各向异性”Astrophys.J.. 529. 26-37 (2000)

K.Tomita,H.Asada,T.Hamana: "Distances in Inhomogeneous Cosmological Models" Progress of Theoretical Physics,Supplement. 131号(発表予定). (1999)

K. Tomita、H. Asada、T. Hamana：“非均匀宇宙学模型中的距离”，《理论物理学进展》，增刊第 131 期（待出版）。

冨田憲二: "Distances and Lensing in Cosmological Void Models"Astrophys.J.. 529. 38-46 (2000)

Kenji Tomita：“宇宙空洞模型中的距离和透镜”Astrophys.J.. 529. 38-46 (2000)