Targeted search for the kinematic dipole of the gravitational-wave background
Targeted search for the kinematic dipole of the gravitational-wave background
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DOI：
10.1103/physrevd.106.082005
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发表时间：
2022-08
影响因子：
5
通讯作者：
A. K. Chung;A. Jenkins;J. Romano;M. Sakellariadou
中科院分区：
文献类型：
--
作者：
A. K. Chung;A. Jenkins;J. Romano;M. Sakellariadou
人们对使用当前和未来的引力波干涉仪来寻找引力波背景中的各向异性越来越感兴趣。一个有保证的各向异性信号是由我们相对于宇宙静止坐标系的特殊运动引起的运动偶极子，正如在其他全天观测中测量的那样，如宇宙微波背景。我们先前对这个偶极子的振幅和方向的了解在LIGO/Virgo/KAGRA现有的搜索中没有明确说明，但可以提供关键信息，帮助解开导致引力波背景的来源。在这里，我们开发了一个有针对性的搜索管道，它使用这种先验知识，使无偏和最小方差的偶极子幅度推断。我们的搜索概括了现有的方法，以允许一个随时间变化的信号模型，它捕获了由于地球轨道的偶极子的年度调制。我们在模拟数据上验证了我们的流水线，证明忽略这种时间依赖性可以使推断的偶极偏差高达O（10%）。然后，我们对完整的LIGO/Virgo O 1 +O2+O3数据集进行分析，获得了与现有各向异性搜索结果一致的偶极振幅上限。
There is growing interest in using current and future gravitational-wave interferometers to search for anisotropies in the gravitational-wave background. One guaranteed anisotropic signal is the kinematic dipole induced by our peculiar motion with respect to the cosmic rest frame, as measured in other full-sky observables such as the cosmic microwave background. Our prior knowledge of the amplitude and direction of this dipole is not explicitly accounted for in existing searches by LIGO/Virgo/KAGRA, but could provide crucial information to help disentangle the sources which contribute to the gravitational-wave background. Here we develop a targeted search pipeline which uses this prior knowledge to enable unbiased and minimum-variance inference of the dipole magnitude. Our search generalises existing methods to allow for a time-dependent signal model, which captures the annual modulation of the dipole due to the Earth’s orbit. We validate our pipeline on mock data, demonstrating that neglecting this time dependence can bias the inferred dipole by as much as O (10%) . We then run our analysis on the full LIGO/Virgo O1+O2+O3 dataset, obtaining upper limits on the dipole amplitude that are consistent with existing anisotropic search results.