Constraining the Equation of State of Neutron Stars with third-generation Gravitational Wave detectors
利用第三代引力波探测器约束中子星状态方程
We investigated the impact of the number of binary neutron star merger events and neutron star (NS) mass distributions on constraining the equation of state (EoS), tidal deformability and radius of NSs, as well as the nuclear parameters, using binary neutron star inspiral gravitational wave signals with third-generation detectors. We generate simulated gravitational wave signals and compute the Fisher information matrix for each event after the number of events and mass distribution models are given. The covariance of EoS parameters is obtained by holding the non-EoS waveform parameters fixed at their injected values and accumulating the Fisher matrix over all events. Finally, the posterior samples of EoS, tidal deformability, radius and nuclear parameters are generated based on this covariance matrix. We find that larger number of events lead to tighter constraints due to more observed events and data accumulation, as expected given the increased number of detections. Meanwhile, we note that the mass distribution plays a more important role in constraining the EoS. We compare a realistic bimodal Gaussian distribution, a uniform distribution and another uniform including sub-solar mass NSs. The results show that the uniform distribution yields tighter constraints than bimodal models because it includes more low-mass and massive NSs. This also implies that events near $1.4\,\Msun$ provide partly redundant information about the EoS. Additionally, including sub-solar mass NSs can further improve the constraints by significantly reducing the EoS uncertainties at sub-saturation densities and inner-crust, highlighting the importance of sub-saturation density EoS.
展开 ▾创新点在于量化了质量分布对 3G EoS 约束的影响:均匀分布优于双峰模型,~1.4 M⊙ 事件存在冗余;并首次在 3G 情景下展示亚太阳质量 NS 对低密度/内壳层 EoS 的独特价值。
自 GW170817 的潮汐形变测量以来,Abbott+ 2018 等已把中子星半径与 EoS 约束推进到可量化阶段;对 NS 质量分布的观测约束(如 Alsing+ 2018)也推动着 EoS 推断方法不断细化。本文延续 Zhu+ 2025 的 Fisher 信息矩阵框架,系统评估 3G 网络下事件数与质量分布对核参数约束的影响,发现均匀分布比现实双峰模型更有效,且亚太阳质量 NS 显著改善低密度与内壳层约束。与 Davis+ 2024 的统一壳-核 EoS 约束相比,纯 GW 数据对亚饱和密度仍偏弱,凸显核物理实验的互补价值。未来结合 FRIB 等地面核物理先验与亚太阳质量天体搜索,有望进一步打破核参数简并,推动从低密度壳层到高密度核区的致密物质状态方程约束。
预印本 2026-09-06 · 收录 2026-09-09