How small can an over-spinning body in general relativity?
How small can an over-spinning body in general relativity?
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广义相对论中过度旋转的物体可以有多小？
DOI：
10.1103/physrevd.90.124079
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发表时间：
2014
影响因子：
5
通讯作者：
Pankaj S. Joshi
中科院分区：
文献类型：
--
作者：
Ken-ichi Nakao;Masashi Kimura;Tomohiro Harada;Mandar Patil;Pankaj S. Joshi
克尔奇点的角动量不应该大于一个阈值，这样它就被事件视界包围了：角动量超过阈值的克尔奇点是裸的。这一事实表明，如果我们的宇宙中存在宇宙审查，那么一个没有释放角动量的过度旋转的物体就不可能坍缩成时空奇点。一个简单的运动学估计的两个粒子接近对方支持这一预期，并建议存在一个最小尺寸的过度旋转的机构。但这并不意味着裸奇点附近的几何不能出现。通过分析初始数据，即，通过对旋转物体的快照，我们看到过旋转物体可以产生一种接近克尔裸奇点的几何形状，至少作为一种瞬态构型。
The angular momentum of the Kerr singularity should not be larger than a threshold value so that it is enclosed by an event horizon: The Kerr singularity with the angular momentum exceeding the threshold value is naked. This fact suggests that if the cosmic censorship exists in our Universe, an over-spinning body without releasing its angular momentum cannot collapse to spacetime singularities. A simple kinematical estimate of two particles approaching each other supports this expectation and suggests the existence of a minimum size of an over-spinning body. But this does not imply that the geometry near the naked singularity cannot appear. By analyzing initial data, i.e., a snapshot of a spinning body, we see that an over-spinning body may produce a geometry close to the Kerr naked singularity around itself at least as a transient configuration.