[论文解读] Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

The LIGO Scientific Collaboration, The Virgo Collaboration+1693 more|arXiv (Cornell University)|Apr 17, 2023

Pulsars and Gravitational Waves Research被引用 19

一句话总结

该论文报告对 LIGO–Virgo 网络在完整的第三次观测运行 (O3) 数据中引力透镜效应签名的搜索，详细描述了方法学及在引力波事件中与透镜相关的信号的发现。

ABSTRACT

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects.

研究动机与目标

• 在整次第三次观测运行 (O3) 期间，激励并界定对 LIGO–Virgo 网络中引力透镜签名的搜索。
• 描述用于识别引力波信号中透镜效应所致签名的方法论以及统计框架。
• 报告结果并评估透镜签名的存在性，包括假阳性/假警报相关考量和鲁棒性检验。

提出的方法

• 将引力透镜搜寻技术应用于 LIGO–Virgo 的完整 O3 数据集（并含 KAGRA 合作组的输入）
• 结合透镜信息信号分析与统计度量（例如 false-positive probability、false-alarm probability）来识别候选签名。
• 在工作流程中纳入多频带、基于模板的分析以及机器学习方法。
• 表征信噪比、功率谱密度和其他信号质量诊断，以区分透镜效应与噪声。

实验结果

研究问题

• RQ1 LIGO–Virgo 网络的完整 O3 数据中是否出现引力透镜签名？
• RQ2 在考虑假阳性与假警报的前提下，任何候选透镜签名的统计显著性如何？
• RQ3 潜在透镜签名对探测器噪声和波形建模变化的鲁棒性如何？
• RQ4 基于观测数据和分析管道可以对透镜情景作出哪些约束？

主要发现

• 该研究报告了在 LIGO–Virgo 网络的完整 O3 观测运行中进行的透镜签名搜索结果。
• 分析采用如 false-positive probability 和 false-alarm probability 等统计度量来评估候选签名。
• 该方法整合基于模板、多频带以及可能的机器学习组件来评估引力波信号中的透镜相关特征。
• 论文在评估中讨论了对噪声和仪器引起的伪影的鲁棒性。
• 结果在搜索框架及其对透镜指示的敏感性背景下呈现。