标题： 后牛顿模式振幅与二黑洞数值相对论模拟的比较 显示英文标题

标题： Comparison of post-Newtonian mode amplitudes with numerical relativity simulations of binary black holes

摘要： 来自两个黑洞并合的引力波携带着双黑洞强场动力学的特征。 在这项工作中，我们使用数值相对论模拟和后牛顿理论来研究这种动力学。 后牛顿理论是一种低速展开，假设伴星为点粒子，而数值相对论则将黑洞视为具有视界的扩展物体，并完全捕捉它们的动力学。 从理论上讲，没有任何理由让用这些不同方法计算出的波形彼此一致，尤其是在晚期时黑洞接近光速运动的情况下。 令人惊讶的是，我们发现后牛顿理论中的主要振幅与广义相对论的完整解对于大量球谐模式非常吻合，即使在双星演化的最动态部分也是如此，只有少数模式表现出与数值相对论模拟所发现的不同行为。 特别是，球谐指数 l = m 以及 l = 2, m = 1 的模式在其主导的后牛顿行为上受到的修改最小。 通过后牛顿描述理解这些模式的本质将有助于制定更强场动力学中发射波形的更好模型。 显示英文摘要

摘要： Gravitational waves from the coalescence of two black holes carry the signature of the strong field dynamics of binary black holes. In this work we have used numerical relativity simulations and post-Newtonian theory to investigate this dynamics. Post-Newtonian theory is a low-velocity expansion that assumes the companion bodies to be point-particles, while numerical relativity treats black holes as extended objects with horizons and fully captures their dynamics. There is a priori no reason for the waveforms computed using these disparate methods to agree with each other, especially at late times when the black holes move close to the speed of light. We find, remarkably, that the leading order amplitudes in post-Newtonian theory agree well with the full general relativity solution for a large set of spherical harmonic modes, even in the most dynamical part of the binary evolution, with only some modes showing distinctly different behavior than that found by numerical relativity simulations. In particular, modes with spherical harmonic indices l = m as well as l = 2, m = 1 are least modified from their dominant post-Newtonian behavior. Understanding the nature of these modes in terms of the post-Newtonian description will aid in formulating better models of the emitted waveforms in the strong field regime of the dynamics.