AI 中文总结
本文基于灵活理论无关（FTI）框架，提出检验致密物体自旋诱导多极矩的方法，经合成信号、LIGO-Virgo-KAGRA观测信号测试，预测下一代探测器可将相关约束精度提升两个数量级，用于探究致密双星并合中黑洞的性质。
AI 中文摘要
根据无毛定理，广义相对论中电中性黑洞的多极矩完全由其质量和自旋决定，但对于致密物体而言通常并非如此：中子星或奇异致密物体的多极矩可依赖于其形成历史和内部过程，这些过程编码于物态方程中。此外，它们的自旋诱导多极矩与相同质量和自旋的黑洞不同，会在双星的动力学及发射的引力波上留下印记，因此引力波可用于检验致密双星并合的性质。本文提出一种基于灵活理论无关（FTI）框架的致密物体自旋诱导四极矩和八极矩检验方法。FTI是一种参数化的广义相对论螺旋进检验，可向通用自旋对齐频域波形模型的引力波相位添加后牛顿系数偏差。我们将该检验应用于合成信号，研究自旋诱导四极矩和八极矩的可测量性；接着将其应用于LIGO-Virgo-KAGRA合作组观测的部分信号；最后对下一代地面探测器（如爱因斯坦望远镜和宇宙探索者）进行预测。我们的估计表明，这些探测器将能对自旋诱导四极矩和八极矩分别施加约$10^{-2}$和$10^{-1}$的严格约束，比当前约束紧两个数量级，从而可用于探究致密双星并合中黑洞的性质。
英文摘要
According to the no-hair theorem, the multipole moments of an electrically neutral black hole in general relativity are entirely determined by its mass and spin. However, this is not in general true for compact objects: The multipole moments of neutron stars or exotic compact objects can depend on their formation history and internal processes, which are encoded in an equation of state. Furthermore, their spin-induced multipole moments differ from those of black holes of the same mass and spin, leaving an imprint on the dynamics and emitted gravitational waves of the binary. Gravitational waves can thus be used to test the nature of compact binary coalescences. Here, we present a test of the spin-induced quadrupole and octupole moments of compact objects based on the flexible theory-independent (FTI) framework. FTI is a parameterized inspiral test of general relativity which enables the addition of post-Newtonian coefficient deviations to the gravitational-wave phase of a generic aligned-spin frequency-domain waveform model. We use this test on synthetic signals to study the measurability of spin-induced quadrupole and octupole moments. Next, we apply the test to a subset of signals observed by the LIGO-Virgo-KAGRA Collaboration. Lastly, we present forecasts for next-generation ground-based detectors, such as Einstein Telescope and Cosmic Explorer. Our estimates suggest that these detectors will be capable of placing stringent constraints on the spin-induced quadrupole and octupole moments of $\mathcal{O}(10^{-2})$ and $\mathcal{O}(10^{-1})$ respectively, which is two orders of magnitude tighter than current constraints, and thus on the nature of black holes in a compact binary coalescence.
Comments19 pages, 18 figures
