标题： 具有SpEC的偏心进动双黑洞模拟的参数控制 显示英文标题

标题： Parameter control for eccentric, precessing binary black hole simulations with SpEC

摘要： 数值相对论模拟合并黑洞提供了对双星动力学和发出的引力波信号最准确的描述。 然而，实际考虑因素如不完善的初始数据和初始参数意味着在模拟可用部分的开始达到目标参数，如轨道偏心率或黑洞自旋方向，是具有挑战性的。 在本文中，我们设计了一种方法，使用SpEC生成具有特定目标参数的模拟，即开普勒轨道参数——偏心率、半长轴、平均异常以及黑洞自旋矢量。 该方法是对当前实现零偏心率过程的扩展，它基于一个参数控制循环，该循环迭代地对系统进行数值演化，用解析后牛顿方程拟合轨道，并计算更新的输入参数。 通过SpEC数值模拟，我们展示了轨道偏心率和自旋方向分别在$\leq7$次迭代中的$\lesssim 10^{-3}$和$O(\rm degree)$收敛性。 这些测试扩展到质量比为$q \leq 3$、偏心率为$e \leq 0.65$以及自旋幅度为$|\chi | \leq 0.75$的双星系统。 我们用于控制数值模拟轨道和自旋参数的方法可用于在参数空间覆盖稀疏的区域生成目标模拟或研究相对论双星的动力学。 显示英文摘要

摘要： Numerical relativity simulations of merging black holes provide the most accurate description of the binary dynamics and the emitted gravitational wave signal. However, practical considerations such as imperfect initial data and initial parameters mean that achieving target parameters, such as the orbital eccentricity or the black hole spin directions, at the beginning of the usable part of the simulation is challenging. In this paper, we devise a method to produce simulations with specific target parameters, namely the Keplerian orbital parameters-eccentricity, semimajor axis, mean anomaly-and the black hole spin vectors using SpEC. The method is an extension of the current process for achieving vanishing eccentricity and it is based on a parameter control loop that iteratively numerically evolves the system, fits the orbit with analytical post-Newtonian equations, and calculates updated input parameters. Through SpEC numerical simulations, we demonstrate $\lesssim 10^{-3}$ and $O(\rm degree)$ convergence for the orbital eccentricity and the spin directions respectively in $\leq7$ iterations. These tests extend to binaries with mass ratios $q \leq 3$, eccentricities $e \leq 0.65$, and spin magnitudes $|\chi | \leq 0.75$. Our method for controlling the orbital and spin parameters of numerical simulations can be used to produce targeted simulations in sparsely covered regions of the parameter space or study the dynamics of relativistic binaries.