Effective-one-body waveforms for binary neutron stars using surrogate models
Effective-one-body waveforms for binary neutron stars using surrogate models
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DOI：
10.1103/physrevd.95.104036
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发表时间：
2017-05-30
影响因子：
5
通讯作者：
Van den Broeck, Chris
中科院分区：
文献类型：
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作者：
Lackey, Benjamin D.;Bernuzzi, Sebastiano;Van den Broeck, Chris
双中子星星系统的引力波观测可以提供有关中子星的质量、自旋和结构的信息。然而，这需要精确且计算高效的波形模型，其花费小于或接近1 s的时间来评估以用于执行10（7）-10（8）波形评估的贝叶斯参数估计代码。我们提出了一个代理模型的nonspinning有效单体波形模型与l = 2，3，和4潮汐多极矩再现波形的二进制中子星星的数值模拟合并。该替代物是从有效单体波形幅度和相位数据的紧凑集合构建的，每个数据形成减少的基础。我们发现，12个振幅和7个相位的基本元素是足够的重建任何二元中子星星波形的起始频率为10赫兹。替代品的最大误差为3.8%的振幅（0.04%，不包括合并前的最后100米）和0.043拉德的相位。这导致Advanced LIGO的典型失配为10（-5）-10-（4），取决于组件质量，当两颗恒星的质量>= 2 M圆点时，最坏情况匹配为7 x 10（-4）。在LIGO算法库中实现的版本对于30 Hz的起始频率需要近似0.07 s进行评估，对于10 Hz的起始频率需要近似0.8 s进行评估，导致相对于原始MATLAB代码的加速因子为O（10（3））。这使得参数估计代码运行在几天到几周，而不是几年，我们证明了这一点与嵌套的采样运行，恢复模拟二元中子星星系统的质量和潮汐参数。
Gravitational-wave observations of binary neutron star systems can provide information about the masses, spins, and structure of neutron stars. However, this requires accurate and computationally efficient waveform models that take less than or similar to 1 s to evaluate for use in Bayesian parameter estimation codes that perform 10(7)-10(8) waveform evaluations. We present a surrogate model of a nonspinning effective-one-body waveform model with l = 2, 3, and 4 tidal multipole moments that reproduces waveforms of binary neutron star numerical simulations up to merger. The surrogate is built from compact sets of effective-one-body waveform amplitude and phase data that each form a reduced basis. We find that 12 amplitude and 7 phase basis elements are sufficient to reconstruct any binary neutron star waveform with a starting frequency of 10 Hz. The surrogate has maximum errors of 3.8% in amplitude (0.04% excluding the last 100M before merger) and 0.043 rad in phase. This leads to typical mismatches of 10(-5) -10-(4) for Advanced LIGO depending on the component masses, with a worst case match of 7 x 10(-4) when both stars have masses >= 2 M circle dot. The version implemented in the LIGO Algorithm Library takes similar to 0.07 s to evaluate for a starting frequency of 30 Hz and similar to 0.8 s for a starting frequency of 10 Hz, resulting in a speed-up factor of O(10(3)) relative to the original MATLAB code. This allows parameter estimation codes to run in days to weeks rather than years, and we demonstrate this with a nested sampling run that recovers the masses and tidal parameters of a simulated binary neutron star system.