论文标题
常数-U $ $ Geodesics以painleve-gullstrand形式的镜头时空形式
Constant-$r$ geodesics in the Painleve-Gullstrand form of Lense-Thirring spacetime
论文作者
论文摘要
本文中,我们探索了当前作者最近引入的painleve-gullstrand变体中的非赤道常数 - $ r $(“准圆”)的测量学(Quasi-Circular')地测量学(均为时机和无效)。即使时空不是球体对称性的,但仍然存在常数的壳,仍然存在。径向运动(通过构造)完全微不足道,确定这些常数 - $ r $ Geodesics的允许位置绝对是不平凡的,并且稳定性分析同样棘手。关于角运动,将看到这些常数$ r $ ro孔可以表现出进动和肉类 - 通常具有不稳定的频率。 Thus this constant-$r$ geodesic motion, though integrable in the precise technical sense, is generically surface-filling, with the orbits completely covering a symmetric equatorial band which is a segment of a spherical surface, (a so-called "spherical zone"), and whose latitudinal extent is governed by delicate interplay between the orbital angular momentum and the Carter constant.这种情况在质量上与(确切的)Kerr Spacetime相似 - 但是我们现在看到,与一般相对性相同的慢旋转弱场限制的任何物理模型仍然将具有非赤道常数-U $ $ r $地理器。
Herein we explore the non-equatorial constant-$r$ ("quasi-circular") geodesics (both timelike and null) in the Painleve-Gullstrand variant of the Lense-Thirring spacetime recently introduced by the current authors. Even though the spacetime is not spherically symmetric, shells of constant-$r$ geodesics still exist. Whereas the radial motion is (by construction) utterly trivial, determining the allowed locations of these constant-$r$ geodesics is decidedly non-trivial, and the stability analysis is equally tricky. Regarding the angular motion, these constant-$r$ orbits will be seen to exhibit both precession and nutation -- typically with incommensurate frequencies. Thus this constant-$r$ geodesic motion, though integrable in the precise technical sense, is generically surface-filling, with the orbits completely covering a symmetric equatorial band which is a segment of a spherical surface, (a so-called "spherical zone"), and whose latitudinal extent is governed by delicate interplay between the orbital angular momentum and the Carter constant. The situation is qualitatively similar to that for the (exact) Kerr spacetime -- but we now see that any physical model having the same slow-rotation weak-field limit as general relativity will still possess non-equatorial constant-$r$ geodesics.