Precession-tracking coordinates for simulations of compact-object-binaries
Precession-tracking coordinates for simulations of compact-object-binaries
复制标题
用于模拟紧凑目标二进制文件的进动跟踪坐标
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
H. Pfeiffer
中科院分区：
文献类型：
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作者：
S. Ossokine;Lawrence E. Kidder;H. Pfeiffer
使用谱方法进行黑洞切除的二元黑洞模拟需要将坐标变换到黑洞基本上处于静止状态的同向旋转坐标系。本文提出并讨论了两种适用于进动二元系统的坐标变换，一种基于欧拉角，另一种基于四元数。研究发现，这两种方法对于具有中等进动的双星（即轨道平面方向变化远小于 90 度的情况）都很有效。对于强进动，欧拉角参数化的性能会恶化，最终由于参数化中的奇点（“万向节锁”）而无法实现 90 度的方向变化。相比之下，四元数表示在整体旋转下是不变的，并且可以处理轨道平面的任何方向，并且欧拉角技术可以处理非进动双星。
Binary black hole simulations with black hole excision using spectral methods require a coordinate transformation into a co-rotating coordinate system where the black holes are essentially at rest. This paper presents and discusses two coordinate transformations that are applicable to precessing binary systems, one based on Euler angles, the other on quaternions. Both approaches are found to work well for binaries with moderate precession, i.e. for cases where the orientation of the orbital plane changes by much less than 90 degrees. For strong precession, performance of the Euler-angle parameterization deteriorates, eventually failing for a 90 degree change in orientation because of singularities in the parameterization ("gimbal lock"). In contrast, the quaternion representation is invariant under an overall rotation, and handles any orientation of the orbital plane as well as the Euler-angle technique handles non-precessing binaries.