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.

在对天体的空间分布和速度进行统计分析的基础上，确定了表征均匀和各向同性宇宙模型的参数(哈勃常数HィイD20ィエD2和减速参数等)。HィイD20ィエD2[大致相当]72 KM SィイD 1-1ィエD 1和M PCィイD 1-1ィエD 1在100Mpc范围内；HィイD20ィエD 2 60 KM SィイD 1-1ィエD 1和M PCィイD 1-1ィエD 1在100~400 Mpc范围内。根据最近的观测，由于Ia型超新星的存在，减速参数是负的(即宇宙的加速度)。另一方面，存在于100Mpc内的体流与Hudson等人发现的宇宙模型的均匀性不相容。(1999)和Willick(1999)。如果我们假设这种体流的存在，一种可能的方法是考虑非齐次宇宙(空洞)模型，以便使理论和观测相一致。该模型由密度较高、哈勃常数较小的外层区域和密度较低、哈勃常数较大的内部(空洞)球状区域组成，并假定观测者(O)的位置偏离中心(C)。在本项目中，我们处理(1)具有上述两个区域的非均匀宇宙学模型，以研究非均匀模型的观测方面；(2)引力透镜零测地线方程的数值模拟，以研究非均匀模型中的宇宙学参数。由于这些工作，我们发现了上述各种观测和理论模型之间的一致性，以及非均匀模型的大量可能性。

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)