发表机构
LIGO Laboratory, Massachusetts Institute of Technology; Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology; Department of Physics, Massachusetts Institute of Technology; Center for Computational Astrophysics, Flatiron Institute; Society of Physicists Interested in Non-aligned Spins, SPINS（麻省理工学院激光干涉引力波天文台; 麻省理工学院卡弗里天体物理与空间研究所; 麻省理工学院物理系; 纽约大学柯朗数学科学研究所计算天体物理学中心; 非对齐自旋物理学家协会）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文表明，引力波数据中黑洞自旋优先在轨道平面内的推断可能源于先验简并，而非真实物理，并提出几何图像揭示其虚假性。
AI 中文摘要
引力波携带了并合双黑洞自旋的信息。其自旋相对于轨道方向的取向（“倾斜角”）虽然难以测量，但能区分并合黑洞双星可能形成的天体物理形成机制。多项分析曾报告有初步证据表明，黑洞自旋倾向于优先排列在双星轨道平面内。我们表明，这些结果很可能是从更易测量的“有效自旋”参数外推得出的，这些参数表征了黑洞双星的引力波旋进，但可能无法唯一约束其天体物理形成。特别是，我们仅利用边缘有效自旋分布的信息，就重现了自旋倾斜角分布中的一个峰。我们提出一个几何图像来比较有效自旋约束与标准种群建模假设，表明当前对优先自旋取向的推断是虚假的。
英文摘要
Gravitational waves carry information on the spins of merging binary-black holes. The orientations of their spins relative to their orbits ("tilts")---while challenging to measure---differentiate the astrophysical formation mechanisms by which merging black hole binaries may form. Multiple analyses have reported tentative evidence that black hole spins are preferentially oriented in the plane of the binary orbit. We show that these results are likely extrapolated from more easily measurable "effective spin" parameters which characterize the gravitational-wave inspiral of black hole binaries but may not uniquely constrain their astrophysical formation. In particular, we reproduce a peak in the spin tilt distribution with information about the marginal effective spin distributions alone. We propose a geometric picture to compare constraints on effective spins to standard population modeling assumptions, suggesting that current inferences of a preferred spin orientation are spurious.
Comments5 pages, 4 figures. Comments welcome!
