Removing degeneracy and multimodality in gravitational wave source parameters
Removing degeneracy and multimodality in gravitational wave source parameters
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DOI：
10.1103/physrevd.106.123015
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发表时间：
2022-07
影响因子：
5
通讯作者：
Javier Roulet;S. Olsen;Jonathan Mushkin;Tousif Islam;T. Venumadhav;B. Zackay;M. Zaldarriaga
中科院分区：
文献类型：
--
作者：
Javier Roulet;S. Olsen;Jonathan Mushkin;Tousif Islam;T. Venumadhav;B. Zackay;M. Zaldarriaga
准圆双黑洞合并由 15 个参数描述，其中引力波观测通常只能不同程度地约束 $\sim 10$ 个独立组合。在这项工作中，我们设计了消除相关性的坐标，并区分了测量良好和测量不良的数量。此外，我们将后验中的近似离散对称性确定为多模态的主要原因，并设计了一种方法来解决此类多模态。得到的后验几乎没有结构，可以有效、稳健地采样。我们提供了一个用于参数估计的 Python 包 cogwheel，它与其他算法一起实现这些方法以加速推理过程。我们引入的坐标之一是自旋方位角，在多个事件中测量得非常好。我们认为这可能是轨道进动的敏感指标，并且我们预计它将揭示自然界中自旋轨道错位的发生。
Quasicircular binary black hole mergers are described by 15 parameters, of which gravitational wave observations can typically constrain only $\sim 10$ independent combinations to varying degree. In this work, we devise coordinates that remove correlations, and disentangle well- and poorly-measured quantities. Additionally, we identify approximate discrete symmetries in the posterior as the primary cause of multimodality, and design a method to tackle this type of multimodality. The resulting posteriors have little structure and can be sampled efficiently and robustly. We provide a Python package for parameter estimation, cogwheel, that implements these methods together with other algorithms for accelerating the inference process. One of the coordinates we introduce is a spin azimuth that is measured remarkably well in several events. We suggest this might be a sensitive indicator of orbital precession, and we anticipate that it will shed light on the occurrence of spin-orbit misalignment in nature.