Investigating the impact of quasiuniversal relations on neutron star constraints in third-generation detectors
准普适关系对第三代探测器中子星约束的影响研究
Gravitational-wave observations of binary neutron star systems can shed light on the currently unknown dense matter equation of state. The equation of state determines a large number of neutron star properties, such as tidal deformability, radius, and quadrupole moment, several of which directly affect the emitted gravitational-wave signals. To reduce the dimensionality when computing gravitational waves and when interpreting observational data, quasiuniversal relations are commonly employed to connect different neutron star properties. However, quasiuniversal relations are not exact, and their use may introduce uncertainty and bias. We explore the potential biases arising from different quasiuniversal relations in the third-generation era: (i) the Love-Q relation connecting the spin-induced quadrupole moment and the tidal deformability, (ii) the relation between the fundamental mode frequency and the tidal deformability, and (iii) the binary Love relation. We find that for the quadrupole relation biases are only present for rapidly rotating systems, for the binary-Love relation induces moderate biases only in the next-to-leading-order tidal parameters, which can, however, propagate into the inferred equation of state at low masses. Regarding fundamental mode frequencies, we find that the employed relation introduces only negligible biases, while waveform systematic effects can become comparatively large. Our results highlight that, while quasiuniversal relations remain a useful tool within gravitational-wave analyses, careful treatment is needed to avoid biases in equation-of-state measurements with next-generation detectors.
展开 ▾系统检验了极端状态方程下三类准普适关系在第三代探测器中的偏差,并通过重拟合动态潮汐成分分离了关系偏差与波形系统误差;发现 f-mode 关系偏差小于波形系统误差,而二元 Love 关系会在低质量端污染状态方程推断。
自 Yagi & Yunes 2013b 提出 I-Love-Q 关系以来,准普适关系已成为从双中子星波形提取潮汐形变率并约束致密物质状态方程的重要工具;Raithel & Most 2022 指出质量-半径斜率极端或含相变的状态方程可能导致关系失准。本文用两种“极端但满足观测”的状态方程,在爱因斯坦望远镜级灵敏度下系统检验了三类准普适关系在单事件参数与层级状态方程约束中的偏差,并通过重拟合 Abac+ 2024 的 NRTidalv3 动态潮汐成分,区分了关系偏差与波形拟合系统误差。结果显示,自旋诱导四极矩关系的偏差主要出现在较快旋转系统,二元 Love 关系对次阶潮汐参数的偏差可传播至低质量状态方程,而 f-mode 关系在层级层面的偏差几乎可忽略。未来可望在波形模型中直接采用 f-mode 频率以规避唯象拟合误差,发展旋转依赖的准普适关系扩展,并对 Yagi & Yunes 2016 提出的 binary Love 关系做面向极端状态方程的再校准,以支撑第三代探测器的高精度状态方程测量。
预印本 2026-02-16 · 刊出 2026-07-23 · 收录 2026-08-20