Nonradial stability of marginal stable circular orbits in stationary axisymmetric spacetimes
Nonradial stability of marginal stable circular orbits in stationary axisymmetric spacetimes
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DOI：
10.1103/physrevd.94.064042
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发表时间：
2016-05
影响因子：
5
通讯作者：
T. Ono;Tomohito Suzuki;H. Asada
中科院分区：
文献类型：
--
作者：
T. Ono;Tomohito Suzuki;H. Asada
我们研究了定常轴对称时空中边缘稳定圆轨道的线性非径向摄动和稳定性，如测试粒子的最内稳定圆轨道，它相对于赤道平面具有反射对称性。根据实验粒子的度规分量、比能量和角动量，得到了天顶稳定性判据。将该方法应用于爱因斯坦方程的Kerr解和Majudar-Papapetrou解。此外，我们重新考察了最近由Johannsen和Psaltis[Phys]提出的快速旋转黑洞的修正度规的边缘稳定圆轨道。修订本D 83,124015(2011年)]。我们发现，对于Johannsen和Psaltis模型，在某些参数区域内对径向扰动稳定的圆形轨道在天顶扰动下变得不稳定。这表明，该模型的最后一个圆形轨道可能比最里面稳定的圆形轨道大。
We study linear nonradial perturbations and stability of a marginal stable circular orbit such as the innermost stable circular orbit of a test particle in stationary axisymmetric spacetimes which possess a reflection symmetry with respect to the equatorial plane. A zenithal stability criterion is obtained in terms of the metric components, the specific energy, and angular momentum of a test particle. The proposed approach is applied to the Kerr solution and Majumdar-Papapetrou solution to the Einstein equation. Moreover, we reexamine marginal stable circular orbits for a modified metric of a rapidly spinning black hole that has been recently proposed by Johannsen and Psaltis [Phys. Rev. D 83, 124015 (2011)]. We show that, for the Johannsen and Psaltis model, circular orbits that are stable against radial perturbations for some parameter region become unstable against zenithal perturbations. This suggests that the last circular orbit for this model may be larger than the innermost stable circular orbit.