论文标题

评估重力波的模型波形精度

Assessing the model waveform accuracy of gravitational waves

论文作者

Hu, Qian, Veitch, John

论文摘要

随着重力波(GW)检测器的灵敏度的提高以及GW来源的多样性的增加,非常需要准确的GW波形模型进行数据分析。尽管当前的模型精度评估需要数值相对论(NR)模拟产生的波形作为“ True波形”,但在本文中,我们提出了一种评估方法,该方法不需要NR模拟,这使我们能够在参数空间中的任何地方评估模型的准确性。通过测量两个波形模型之间的差异,我们为一组特定的参数提供了一对波形模型的必要条件。然后,我们将此方法应用于重力波瞬态目录GWTC-3和GWTC-2.1的参数估计样品,并发现在某些情况下,高信噪比事件的波形准确性在某些情况下使我们的评估标准失败。基于对真实事件的后验样本的分析,我们讨论了我们的量化精度评估与参数估计中系统错误之间的相关性。我们发现在评估中表现较差的波形模型更有可能给出不一致的估计。我们还研究了不同参数区域中的波形准确性,并在自旋效应上升时发现精度降低,质量比偏离一个,或者轨道平面几乎与视线保持一致。此外,我们对未来检测器的波形准确性要求进行了预测,并找到了至少3个数量级的当前波形模型的准确性,这与以前的工作一致。

With the improvement in sensitivity of gravitational wave (GW) detectors and the increasing diversity of GW sources, there is a strong need for accurate GW waveform models for data analysis. While the current model accuracy assessments require waveforms generated by numerical relativity (NR) simulations as the "true waveforms", in this paper we propose an assessment approach that does not require NR simulations, which enables us to assess model accuracy everywhere in the parameter space. By measuring the difference between two waveform models, we derive a necessary condition for a pair of waveform models to both be accurate, for a particular set of parameters. We then apply this method to the parameter estimation samples of the Gravitational-Wave Transient Catalogs GWTC-3 and GWTC-2.1, and find that the waveform accuracy for high signal-to-noise ratio events in some cases fails our assessment criterion. Based on analysis of real events' posterior samples, we discuss the correlation between our quantified accuracy assessments and systematic errors in parameter estimation. We find waveform models that perform worse in our assessment are more likely to give inconsistent estimations. We also investigate waveform accuracy in different parameter regions, and find the accuracy degrades as the spin effects go up, the mass ratio deviates from one, or the orbital plane is near-aligned to the line of sight. Furthermore, we make predictions of waveform accuracy requirements for future detectors and find the accuracy of current waveform models should be improved by at least 3 orders of magnitude, which is consistent with previous works.

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