标题： 超叠加旋转黑洞的初始数据 显示英文标题

标题： Initial data for superposed rotating black holes

摘要： 求解黑洞碰撞的初始数据的标准方法是使用共形平坦的初始几何结构。 与其他优点相比，这种选择允许任意质量、位置和自旋的黑洞的简单叠加。 然而，共形平坦的限制不适合研究Kerr黑洞，因为标准的等时间切片不是共形平坦的。 在这里，我们指出，对于旋转黑洞的轴对称排列，可以选择一种非共形平坦的三维几何形式，该形式允许任意质量和自旋的Kerr黑洞的相对简单的叠加。 我们提出了表示远距离局部Kerr黑洞的初始数据解，以及表示旋转黑洞足够接近以至于在共同视界之外，时空几何是一个单个Kerr黑洞的微扰的初始数据解。 显示英文摘要

摘要： The standard approach to initial data for both analytic and numerical computations of black hole collisions has been to use conformally-flat initial geometry. Among other advantages, this choice allows the simple superposition of holes with arbitrary mass, location and spin. The conformally flat restriction, however, is inappropriate to the study of Kerr holes, for which the standard constant-time slice is not conformally flat. Here we point out that for axisymmetric arrangements of rotating holes, a nonconformally flat form of the 3-geometry can be chosen which allows fairly simple superposition of Kerr holes with arbitrary mass and spin. We present initial data solutions representing locally Kerr holes at large separation, and representing rotating holes close enough so that outside a common horizon the spacetime geometry is a perturbation of a single Kerr hole.