Linear and Nonlinear Tides in Coalescing Binary Neutron Stars

该项目由引力物理计划和已建立的激励竞争性研究计划(EPSCoR)共同资助。潮汐相互作用导致月球总是以同一面面对地球，这也影响了双星中子星(BNSS)的合并，在双星的引力波(GW)信号上留下了明显的印记。LIGO和处女座发现的BNS事件GW190817展示了研究BNS中潮汐的巨大科学潜力。该奖项将支持以第一原理理论为基础研究BNSS中的潮汐相互作用及其对GW观测的影响。它还将促进对一名研究生进行最先进的分析和计算方法的培训，为美国的STEM劳动力做出贡献。除科学研究外，还将开展外联活动，让妇女和其他在STEM领域任职人数不足的少数群体参与进来。为了推进描述潮汐相互作用的分析模型，将考虑被称为非线性潮汐的非线性水动力相互作用。这将涉及到将扰动流体运动扩展到本征模式，并考虑这些模式之间的非线性耦合。然后，模的演化将与GW驱动的轨道衰变耦合在一起。有人提出，考虑非线性潮汐可以加强分析模型与基于牛顿量级潮汐计算的数值相对论模拟之间的一致性。计算将扩展到后牛顿阶数，从而产生易于应用的模板，用于GW数据分析和与数值相对论的比较。此外，还将进一步探索中子星自转和双星偏心率的并入。在这个项目中开发的某些计算工具将在网上公开，促进合作和促进科学进步。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project is jointly funded by the Gravitational Physics program and the Established Program to Stimulate Competitive Research (EPSCoR). Tidal interactions, which result in the Moon always facing the Earth with the same side, also impact the coalescence of binary neutron stars (BNSs), leaving a noticeable imprint on the gravitational wave (GW) signal of the binary. The discovery of the BNS event GW190817 by LIGO and Virgo has demonstrated the immense scientific potential of studying tides in BNSs. This award will support research into investigating tidal interactions in BNSs based on first-principle theories and their implications for GW observations. It will also facilitate the training of a graduate student in state-of-the-art analytical and computational methods, contributing to the STEM workforce in the United States. In addition to scientific research, outreach activities will be developed to engage women and other underrepresented minorities in STEM fields. To advance analytical models describing tidal interactions, nonlinear hydrodynamical interactions, referred to as nonlinear tides, will be taken into account. This will involve expanding the perturbed fluid motion into eigenmodes and considering the nonlinear couplings among these modes. The evolution of the modes will then be coupled with the GW-driven orbital decay. It has been suggested that incorporating nonlinear tides may enhance the agreement between analytical models and numerical relativity simulations based on tidal calculations at the Newtonian order. The calculations will be extended to post-Newtonian orders, resulting in readily applicable templates for GW data analysis and comparison with numerical relativity. Additionally, the incorporation of neutron star spins and binary eccentricities will be further explored. Certain computational tools developed during this project will be made publicly accessible online, fostering collaboration and facilitating scientific advancements.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.