Studies on general-relativistic astrophysical phenomena

在这个研究项目中，我们涵盖了宇宙所有时空尺度上的广义相对论天体物理现象，并试图阐明它们之间的相互联系。2000-2003会计年度历时4年，取得了许多有价值的研究成果。它们被分为三类：(1)大爆炸附近非常早期的时空结构；(2)空间小尺度上的现象(引力波、高密度恒星和黑洞)；(3)空间大尺度上的现象(不均匀、大尺度结构和引力透镜)。其中的显著成果是：(1)广泛地介绍和研究了多维薄膜世界和我们的宇宙作为其四维截面的理论；(2)建立了引力波天体物理的框架，开始阐明伽马射线暴的形成机制；(3)进行了各种宇宙学观测(如WMAP、SDSS等)，在假设宇宙学原理的基础上确定了宇宙模型参数，并澄清了暗能量的存在。在大阪大学、早稻田大学、东京大学和大阪市立大学举办的广义相对论和引力讲习班、“宇宙学和引力前沿”讲习班以及其他国际会议上报告了许多成果。这些研讨会和会议对我们这个领域的年轻医生的国际交流和教育很有帮助。

In this study project we covered the general-relativistic astrophysical phenomena on all space-and-time scales of the Universe and tried to clarify their mutual connections. The studies were performed for 4 years from 2000 to 2003 fiscal year, and many valuable results were obtained. They are classified into three groups : (1) the space-time structure at the very early stages in the neighborhood of the big-bang, (2) phenomena on spatially small scales (gravitational waves, high density stars and black holes), and (3) phenomena on spatially large scales (the non-uniformity, large-scale structures and gravitational lensing). In each of them, the remarkable results are that (1) theories on the multidimensional brane world and our Universe as its four-dimensional section were introduced and studied extensively, (2) the framework of gravitational-wave astrophysics was constructed and the formation mechanism of gamma-ray bursts began to be clarified, and (3) various cosmological observations (like WMAP, SDSS etc) were executed, the cosmological model parameters were determined assuming the cosmological principle and the existence of dark energy was clarified. Many of these results were reported in the Workshops of General Relativity and Gravitation held in Osaka University, Waseda University, University of Tokyo and Osaka City University, and in Workshop of "Frontiers of Cosmology and Gravitation" as well as the other international conferences. These Workshops and conferences were useful for the international communications and the education of young physists in our field.