标题： 克尔黑洞的准正模与激发因子 显示英文标题

标题： Quasinormal modes and excitation factors of Kerr black holes

摘要： 对受扰黑洞的特征振荡（也称为准正模，QNMs）的理论理解对于解释我们现在在引力波探测器中常规观测到的双黑洞合并晚期阶段至关重要。 在这项工作中，我们引入了一种基于广义Sasaki-Nakamura形式主义的新方法，用于计算标量、电磁和引力扰动的QNM谱及其激发因子（QNEFs）。使用这种方法，QNM波函数在视界和空间无穷远处都保持有限。 我们的结果通常与之前使用不同方法进行的计算一致，尽管我们进一步澄清了QNEFs及其随黑洞质量的变化依赖于扰动的自旋权重。 我们展示了避免交叉并不是一种普遍现象：特征值的实部或虚部可以彼此交叉，但不会同时两者都交叉，并且当一个部分发生交叉时，另一个部分会出现排斥。 尽管光谱仅依赖于实值黑洞角动量，但由于分支点奇异性引起的特征值排斥在QNM光谱中仍然起着重要作用。 显示英文摘要

摘要： Theoretical understanding of the characteristic oscillations of a perturbed black hole, also referred to as quasinormal modes (QNMs), is crucial to interpreting the late stage of binary black hole mergers that we now routinely observe in gravitational wave detectors. In this work, we introduce a new approach, based on the generalized Sasaki-Nakamura formalism, to compute the QNM spectra and their excitation factors (QNEFs), for scalar, electromagnetic and gravitational perturbations. Using this approach, QNM wavefunctions remain finite at the horizon and spatial infinity. Our results in general agree with previous calculations that were performed using different methods, though we further clarify that QNEFs and their scaling with the mass of the black hole depend on the spin-weight of the perturbation. We show that avoided crossing is not a general phenomenon: the real or the imaginary part of the eigenvalues can cross each other but not both simultaneously, and when crossing occurs in one part, repulsion follows in the another part. Eigenvalue repulsion, originating from branch point singularities, still plays an important role in the QNM spectra, despite the fact that the spectra depend only on the real-valued black hole angular momentum.