Surrogate model of hybridized numerical relativity binary black hole waveforms
Surrogate model of hybridized numerical relativity binary black hole waveforms
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DOI：
10.1103/physrevd.99.064045
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发表时间：
2018-12
影响因子：
5
通讯作者：
V. Varma;Scott E. Field;M. Scheel;J. Blackman;Lawrence E. Kidder;H. Pfeiffer
中科院分区：
文献类型：
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作者：
V. Varma;Scott E. Field;M. Scheel;J. Blackman;Lawrence E. Kidder;H. Pfeiffer
数值相对论（NR）模拟提供了最精确的双黑洞引力波形，但对于参数估计等应用来说过于昂贵。NR波形的替代模型已被证明是快速和准确的。然而，基于NR的代理模型受到训练波形长度的限制，其通常在合并前约为20个轨道。我们补救这一点，通过杂交的NR波形使用后牛顿和有效的单体波形的早期inspiral。我们提出了NRHybSur 3dq 8，杂交nonprecessing数值相对论波形的代理模型，这是有效的整个LIGO波段（从20 Hz开始）的恒星质量双星的总质量低至2.25 M。我们包括l ≤ 4和（5，5）自旋加权球谐模，但不包括（4，1）或（4，0）模。该模型已经针对基于质量比q ≤ 8的104个NR波形的混合波形进行了训练，并且|χ_（1z）|,|χ_（2z）|≤ 0.8，其中χ_（1 z）（χ_（2 z））是较重（较轻）黑洞在轨道角动量方向上的自旋。替代物精确地再现了混合波形，在2.25 M <$≤ M ≤ 300 M <$的质量范围内失配为<$3 ×10^（−4）。在高质量（M 40 M），合并和振铃是更突出的，我们显示了大约2个数量级的改善，现有的波形模型。我们还表明，即使在其训练参数空间范围之外外推时，代理也能很好地工作，包括在高达0.998的自旋时。最后，我们表明，该模型准确地再现了球体，球形模式混合NR振铃信号中存在的。
Numerical relativity (NR) simulations provide the most accurate binary black hole gravitational waveforms, but are prohibitively expensive for applications such as parameter estimation. Surrogate models of NR waveforms have been shown to be both fast and accurate. However, NR-based surrogate models are limited by the training waveforms’ length, which is typically about 20 orbits before merger. We remedy this by hybridizing the NR waveforms using both post-Newtonian and effective one-body waveforms for the early inspiral. We present NRHybSur3dq8, a surrogate model for hybridized nonprecessing numerical relativity waveforms, that is valid for the entire LIGO band (starting at 20 Hz) for stellar mass binaries with total masses as low as 2.25 M⊙. We include the l ≤ 4 and (5, 5) spin-weighted spherical harmonic modes but not the (4, 1) or (4, 0) modes. This model has been trained against hybridized waveforms based on 104 NR waveforms with mass ratios q ≤ 8, and |χ_(1z)|,|χ_(2z)| ≤ 0.8, where χ_(1z) (χ_(2z)) is the spin of the heavier (lighter) black hole in the direction of orbital angular momentum. The surrogate reproduces the hybrid waveforms accurately, with mismatches ≲ 3×10^(−4) over the mass range 2.25 M⊙ ≤ M ≤ 300 M⊙. At high masses (M ≳ 40 M⊙), where the merger and ringdown are more prominent, we show roughly 2 orders of magnitude improvement over existing waveform models. We also show that the surrogate works well even when extrapolated outside its training parameter space range, including at spins as large as 0.998. Finally, we show that this model accurately reproduces the spheroidal-spherical mode mixing present in the NR ringdown signal.