论文标题
光在紧凑物体的光子球周围的光偏转无偏转
Nondivergent deflection of light around a photon sphere of a compact object
论文作者
论文摘要
我们证明，稳定的光子球（PS）在紧凑的物体中的位置并不总是一个边缘，例如黑洞阴影的内部边界，而不稳定的PS的位置众所周知是Schwarzschild Black Hole中的阴影边缘。如果静态球形对称（SSS）时空具有稳定的最外面的PS，则空间不能渐近地平坦。尽管已知在大多数具有不稳定的光子球体的SSS紧凑型物体中出现了对数发散的行为，但对于稳定的PS传播的光子引起了无散的挠度。非差异的原因是，当光子从镜头远离镜头对象的源（或到达接收器）发射时，稳定PS的直接附近禁止光子的最接近方法。有限的间隙大小取决于接收器和镜头和镜头参数的源距离。轻度偏转角可以通过弧形功能近似。 Weyl重力中的一类SSS溶液例证了稳定的外部PS附近的非散发偏转。
We demonstrate that the location of a stable photon sphere (PS) in a compact object is not always an edge such as the inner boundary of a black hole shadow, whereas the location of an unstable PS is known to be the shadow edge notably in the Schwarzschild black hole. If a static spherically symmetric (SSS) spacetime has the stable outermost PS, the spacetime cannot be asymptotically flat. A nondivergent deflection is caused for a photon traveling around a stable PS, though a logarithmic divergent behavior is known to appear in most of SSS compact objects with an unstable photon sphere. The reason for the nondivergence is that the closest approach of a photon is prohibited in the immediate vicinity of the stable PS when the photon is emitted from a source (or reaches a receiver) distant from a lens object. The finite gap size depends on the receiver and source distances from the lens as well as the lens parameters. The mild deflection angle of light can be approximated by an arcsine function. A class of SSS solutions in Weyl gravity exemplify the nondivergent deflection near the stable outer PS.
