A Method of Determining Apparent Horizons in [(2+1)+1]-Formalism of the Einstein Equations
A Method of Determining Apparent Horizons in [(2+1)+1]-Formalism of the Einstein Equations
复制标题
爱因斯坦方程[(2 1) 1]-形式中视视界的确定方法
DOI：
10.1143/ptp.63.1051
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发表时间：
1980
影响因子：
--
通讯作者：
Takashi Nakamura
中科院分区：
文献类型：
--
作者：
M. Sasaki;K. Maeda;S. Miyama;Takashi Nakamura
当我们处理引力塌缩问题时，我们应该确定一个事件视界，以便知道黑洞是否形成。当时空的整体结构已知时，就可以确定事件视界。然而，在轴对称恒星广义相对论坍缩的数值计算中，我们需要太多的核心存储器来确定事件视界，因为我们应该知道任意时空点的度量张量的值。另一方面，如果已知 t=const 类空间超曲面 (Z (t)) 的第一和第二基本形式，则可以确定表观视界。因此，在数值计算中，确定始终存在于事件视界内部的视视界比确定事件视界更为实用。表观地平线是一个边缘捕获的表面，在该表面上传出的正交零测地线具有零膨胀，u
When we deal with the problems of gravitational collapse, we should determine an event horizon in order to know whether a black hole is formed or not. It is possible to determine the event horizon when the global structure of the space-time is known. However, in the numerical calculation of the general relativistic collapse of an axially symmetric star we need too many core memories to determine the event horizon because we should know the values of the metric tensors at any space-time points. On the other hand, an apparent horizon can be determined if the first and the second fundamental forms of t=const spacelike hypersurface (Z (t)) are known. So in numerical calculations, it is more practical to determine an apparent horizon which always exists inside an event horizon than to determine an event horizon. An apparent horizon is a marginally trapped surface on which the outgoing orthogonal null geodesics have zero expansion,u