Relativistic Astrophysics Based on Brane Cosmologyブレイン宇宙モデルに基づく相対論的宇宙物理学

点击翻译按钮获取中文摘要

The idea of "brane", which appeared in string theory, changes completely the view of the early universe and strong gravitational phenomena. It also changes the view of higher dimensions from the conventional old idea by Kaluza and Klein, i.e., the existence of a brane makes a large extra dimension possible and visible. Furthermore new brane models proposed by Randall and Sundrum give new types of compactification mechanism. Especially, the second model has become the focus of cosmologist's attention because it gives the Newtonian gravity in higher dimensional world without compactification. This model provides definitely a different aspect from the conventional Kaluza-Klein compactification. Hence many relativists and cosmologists are studying it to look for new world view. Under such a circumstance, it is very important to analyze cosmological models and strong gravitational phenomena such as a black hole or gravitational collapse based on this brane gravitational theory. In this research project, we study new view of the brane world with the help of two prominent young professors (David Wands and David Langlois).In order to clarify the properties of brane gravity, we have studied brane collision in the ekpyrotic cosmological model, which could be an alternative of the standard inflation scenario, and the reheating mechanism, which leads the universe to a big bang. We have also analyzed some effective theories with higher curvature terms, which come from quantum correction of string theory discussed their cosmological models, and proposed new inflationary scenario.