Theoretical study of gravitational collapse of topological defects and of their stability under the higher dimensional gravity

高维引力下拓扑缺陷的引力塌陷及其稳定性的理论研究

基本信息

批准号：
16540264
负责人：
NAKAO Ken-ichi
金额：
$ 1.15万
依托单位：
Osaka City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

It is a purpose of this research project to get knowledge about the gravitational collapse to form black strings as a peculiar phenomenon under the higher dimensional gravity. And further, using the knowledge obtained, I would study the gravitational collapse of cosmic strings and domain walls whose have infinite extent of energy distribution.Together with my collaborators, I investigated 4-dimensional spacelike hypersurfaces on which a mass distributes homogeneously within an ellipsoidal region. We search for apparent horizons on these spacelike hypersurfaces and confirm the so-called hyperhoop conjecture about the necessary and sufficient condition for the formations of black objects in higher dimensional spacetime.Together with my collaborators, I proposed a scenario of the black string formation by the collisions and mergers of type I cosmic strings and found that even if the tension of the type I cosmic string is almost equal to the energy scale of electroweek phase transition, the black strings will form if such type I cosmic strings exist in out universe.Since a domain wall has a 2-dimantional spatial extent, its spatial codimension is two in the 5-dimensional brane world scenario. Thus a domain wall in the 5-dimensional brane world scenario will behave as a cosmic string in 4-dimensional spacetime. In general it is very difficult to treat a spacetime singularity with spatial codimension 2. Thus I also studied the gravitational collapse with cylindrical symmetry, which form a spacetime singularity with codimension 2. Further, I studied the inflation which occurs within a topological defect, and the cosmological gravitational lensing effects which might observationally reveal the existence of black objects in our universe.

该研究项目的目的是了解引力崩溃，以形成黑色弦作为在较高维度下的特殊现象。此外，使用所获得的知识，我将研究宇宙弦和域壁的重力崩溃，它们具有无限的能量分布程度。与我的合作者进行了合并，我研究了4维间距性超浮标，质量在椭圆形区域内质量分布。我们在这些型超曲面上寻找明显的范围，并确认所谓的超霍普猜想，内容涉及在较高的时空中黑色物体形成的必要条件和足够条件电动相变，如果在宇宙中存在这样的I型宇宙弦，则将形成黑色弦。由于域壁具有二维空间范围，其空间编码在5维的Brane世界情景中是两个。因此，在五维brane世界情景中的域墙将以4维时空的宇宙弦行为。通常，很难用空间的编纂2处理时空的奇异性。因此，我还研究了引力崩溃的圆柱对称性，这形成了与编成拟合2的时空奇异性2。此外，我研究了在拓扑缺陷中发生的通胀，并在拓扑中揭示了拓扑效果，这可能会揭示出黑色对象的宇宙宇宙，即黑色对象。