Optimal Search for an Astrophysical Gravitational-Wave Background
Optimal Search for an Astrophysical Gravitational-Wave Background
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DOI：
10.1103/physrevx.8.021019
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发表时间：
2017-12
影响因子：
12.5
通讯作者：
Rory J. E. Smith;E. Thrane
中科院分区：
文献类型：
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作者：
Rory J. E. Smith;E. Thrane
大约每隔2-10分钟，一对恒星质量的黑洞就会在宇宙中的某个地方合并。这些合并中的一小部分被高级探测器如LIGO和Virgo探测到为单独可分辨的引力波事件。其余的则构成了随机背景。我们推导出了未分辨双星背景下的统计最优搜索策略(产生最小可信区间)。我们的方法将贝叶斯参数估计应用于所有可用数据。通过蒙特卡罗模拟，我们证明了这种搜索既安全又有效：它不会被毛刺等仪器伪影所愚弄，而且它可以无偏地恢复模拟的随机信号。在现实假设下，我们估计搜索可以用大约1天的设计灵敏度数据来探测双星黑洞背景，而不是使用传统的互相关搜索来探测≈40个月。这个框架独立地限制了合并率和黑洞质量分布，打破了互相关方法中存在的简并性。搜索为紧凑双星的种群研究提供了一个统一的框架，这是基于超参数估计的。我们讨论了一些推广和推广，包括应用于其他源(如双中子星和连续波源)，连续高斯背景的同时估计，以及在脉冲星计时中的应用。
Roughly every 2–10 min, a pair of stellar-mass black holes merge somewhere in the Universe. A small fraction of these mergers are detected as individually resolvable gravitational-wave events by advanced detectors such as LIGO and Virgo. The rest contribute to a stochastic background. We derive the statistically optimal search strategy (producing minimum credible intervals) for a background of unresolved binaries. Our method applies Bayesian parameter estimation to all available data. Using Monte Carlo simulations, we demonstrate that the search is both “safe” and effective: it is not fooled by instrumental artifacts such as glitches and it recovers simulated stochastic signals without bias. Given realistic assumptions, we estimate that the search can detect the binary black hole background with about 1 day of design sensitivity data versus ≈40 months using the traditional cross-correlation search. This framework independently constrains the merger rate and black hole mass distribution, breaking a degeneracy present in the cross-correlation approach. The search provides a unified framework for population studies of compact binaries, which is cast in terms of hyperparameter estimation. We discuss a number of extensions and generalizations, including application to other sources (such as binary neutron stars and continuous-wave sources), simultaneous estimation of a continuous Gaussian background, and applications to pulsar timing.