Complete classification of photon escape in the Kerr black hole spacetime
Complete classification of photon escape in the Kerr black hole spacetime
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DOI：
10.1103/physrevd.103.044029
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发表时间：
2020-11
影响因子：
5
通讯作者：
Kota Ogasawara;Takahisa Igata
中科院分区：
文献类型：
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作者：
Kota Ogasawara;Takahisa Igata
我们考虑了从克尔黑洞视界附近发射的光子逃逸到无穷远的充要条件。径向运动方程决定了光子到达无穷大的必要条件，极角运动方程进一步限制了光子运动的允许区域。与赤道平面的发射不同，当发射点的初始极角为任意时，后一种限制对于光子逃逸是至关重要的。我们提供了一个可视化工具来分析这两种情况，并演示了揭示光子逃逸的过程。最后，我们完全确定了光子可以逃逸的二维碰撞参数空间。
We consider necessary and sufficient conditions for photons emitted from the vicinity of a Kerr black hole horizon to escape to infinity. The radial equation of motion determines necessary conditions for photons to reach infinity, and the polar angle equation of motion further restricts the allowed region of photon motion. Unlike emission from the equatorial plane, the latter restrictions are crucial for photon escape when the initial polar angle of the emission point is arbitrary. We provide a visualization tool to analyze these two conditions and demonstrate a procedure for revealing photon escape. Finally, we completely identify the two-dimensional impact parameter space in which photons can escape.