论文标题
小说中最内向的稳定的圆形轨道和阴影，$ 4D $ EINSTEIN-GAUSS-BONNET重力
The innermost stable circular orbit and shadow in the novel $4D$ Einstein-Gauss-Bonnet gravity
论文作者
论文摘要
最近，制定了一种新颖的$ 4D $ EINSTEIN-GAUSS-BONNET（EGB）重力，并在该理论中由球形对称的黑洞解决方案由D. Glavan和C. Lin \ Cite {Glavan：2019inb}得出。在本文中，我们通过专注于最内向的稳定圆形轨道（ISCO）来研究球形对称黑洞的背景中的大地运动动作，以实现巨大的粒子，光子球和阴影。同样，我们发现在该理论中允许负GB耦合常数，因为在这种情况下，黑洞的奇异行为可以隐藏在事件范围内。此外，我们发现，由于此扩展，最近在\ cite {lu：2019zxb}的黑洞大小上的通用绑定可能会被损坏。
Recently, a novel $4D$ Einstein-Gauss-Bonnet (EGB) gravity was formulated and a spherically symmetric black hole solution in this theory was derived by D. Glavan and C. Lin \cite{Glavan:2019inb}. In this paper, we study the geodesic motions in the background of the spherically symmetric black hole, by focusing on the innermost stable circular orbits (ISCO) for massive particle and photon sphere and shadow. Also, we find that a negative GB coupling constant is allowable in this theory, as in which case the singular behavior of the black hole can be hidden inside the event horizon. Moreover, we find that due to this extension a recently proposed universal bound on black hole size in \cite{Lu:2019zxb} can be broken.
