RUI: Neutron Star Oscillations as Probes of Dense Matter Properties and Phases

中子星是一种天体物理物体，其质量与太阳相当，但只有一座城市那么大。人们对中子星内部物质的状态所知甚少，然而，在这种密度极高的条件下，物质的性质对于理解强核力的复杂性至关重要，强核力决定了中子和质子的子结构，而所有的原子都是由中子和质子组成的。最近发现的来自合并中子星的引力波为研究中子星内部的这种致密物质开辟了一条独特的途径。该项目将通过研究这些物质如何影响观测到的引力波的振幅和频率来量化这些物质的特性。这将通过使用爱因斯坦的广义相对论和明智地选择描述强核力的模型来完成。这项研究的主要成果将是通过对引力波数据的分析，为物质的新状态找到最佳的科学证据。此外，PI将在研究过程中对学生进行先进计算方法的培训，并通过教师培训讲习班与高中生分享尖端科学知识。该项目涉及核理论、中子星和引力波的融合领域。在这个项目中，PI将计算非径向中子星振荡的频谱，特别关注那些最有可能在连续发射源的引力波信号中表现出来的模式，这些模式可以约束致密物质的关键属性，如对称能。重点是将量子散射理论中已知的精确和有效的数值方法应用于完全广义相对论中流体振荡谱的计算，同时采用满足当前实验和天体物理约束的中子星物质的选择状态方程（冷或热条件），包括最近的潮汐极化数据。该研究还将通过筛选包含这些方面的选择模型的状态方程数据库，解决影响中子星振荡的致密物质相对未被探索的特征，例如超流动性和相变。该项目将涉及几名研究生，最终完成他们的硕士论文，PI将与科学教育专家合作，向参与实施下一代科学标准（NGSS）的当地高中教师传授天体物理学主题的最新知识。该项目推进了“宇宙之窗：多信使天体物理学时代”的目标，这是美国国家科学基金会未来投资的十大理念之一。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Neutron stars are astrophysical objects that weigh as much as the Sun but are only about as large as a city. Little is known about the state of matter inside neutron stars, yet, the properties of matter in such extremely dense conditions is crucial to understanding the complexities of the strong nuclear force, which determines the sub-structure of neutrons and protons out of which all atoms are made. The recent discovery of gravitational waves from merging neutron stars opens a unique avenue for the study of this dense matter inside neutron stars. This project will quantify the properties of such matter by studying how it impacts the amplitude and frequency of observed gravitational waves. This will be accomplished by using Einstein's general theory of relativity and a judicious selection of models describing the strong nuclear force. The main outcome of this research will be discovering the best lines of scientific evidence for new states of matter from the analysis of gravitational wave data. In addition, the PI will train students on advanced computational methods in the course of this research and share cutting-edge scientific knowledge with high school students via teacher-training workshops.The project addresses the converging domain of nuclear theory, neutron stars and gravitational waves. In this project, the PI will calculate the spectrum of non-radial neutron star oscillations, with particular attention to modes that are most likely to manifest in gravitational wave signals from continuously emitting sources and which can constrain key properties of dense matter such as the symmetry energy. The emphasis is on applying accurate and efficient numerical methods known from quantum scattering theory to the computation of the spectrum of fluid oscillations in full General Relativity, while employing select equations of state (cold or hot conditions) for neutron star matter that satisfy current experimental and astrophysical constraints, including the recent tidal polarizability data. The research will also address relatively unexplored features of dense matter that impact neutron star oscillations, such as superfluidity and phase transitions, by sifting through a database of equation of states for select models that include these aspects. The project will involve several graduate students culminating in their Masters thesis, and the PI will work with experts in science education to communicate current knowledge of topics in astrophysics to local high school teachers involved with implementing next generation science standards (NGSS).This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.