CAREER: Research in Strong-Field Gravity and Astrophysics

该奖项部分由2021年美国救援计划法案（公法117-2）资助。该项目为国家利益服务，正如NSF的使命所述，通过促进科学进步，为促进国家繁荣和福利奠定基础；特别是，该奖项将通过将理论和多信使观测与引力波结合起来，使广义相对论和修正引力中的紧凑双星系统的研究成为可能。这项工作将推进我们对中子星碰撞深处的密度和温度下的核物理的理解，这是地球上无法通过实验来探测的。将开发新的工具，通过LIGO的引力波观测和地面和太空望远镜从无线电到硬伽马射线波段观测到的预期电磁信号的协同作用来理解重力。该小组将在超级计算机的帮助下开发新的代码，用于模拟双中子星和双黑洞-中子星。这样的理论工作对于成功地解释和从现有的和未来的紧致双星系统的观测中提取基本物理是至关重要的。该奖项将支持STEM领域学生的培训、教育和进一步的职业发展，包括少数族裔和女性。该奖项将为即将到来的亚利桑那州科学学生计算和数学计划（COMPASS）的发展提供支持，该计划将为学生从高中到大学的过渡提供桥梁和平滑，并促进在物理、天文学和其他科学领域中未被充分代表的少数民族的成功和保留。具体项目有两个目标：a)推进我们对强场、相对论引力、核物理和理论天体物理的理解；B)促进引力波及其可能的电磁对应物的探测和物理解释。大部分的工作将集中在紧密双星（双中子星，双黑洞-中子星）的激励和合并以及它们的引力波和电磁特征的研究上。将开发方法，利用这些可观察到的特征来提取有关基础物理的信息，特别是关于核饱和密度以上的重力和核物理性质的信息。更具体地说，将开发在超级计算机上运行的代码，以解决标量-张量引力理论的方程，并在未来应用于双黑洞-中子星，以便开发技术，测试是否存在由电荷（暗、电或磁）或磁场触发的任何标量场诱导偏离爱因斯坦引力，并首次测试该制度中的等效原理。利用现有的代码，将开发方法，利用引力波和双中子星合并的电磁特征来探测核密度下状态方程的未知热部分。鉴于最近LIGO和室女座合作探测到的引力波不仅是由双黑洞产生的，而且是由至少有一颗中子星的致密双星产生的，因此提出的研究非常及时。该项目不仅有利于当前和即将到来的引力波探测器和望远镜的解释和探测，也有利于未来的引力波探测器和望远镜的解释和探测。所提出的研究将通过大型超级计算机模拟和分析建模来完成。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。

This award is funded in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The project serves the national interest, as stated by NSF's mission, by promoting the progress of science, and laying foundations that will help advance the national prosperity and welfare; In particular, the award will enable research on compact binary systems in general relativity and modified gravity by combining theory and multi-messenger observations with gravitational waves. The work will advance our understanding of nuclear physics at densities and temperatures that arise in the deep interiors of colliding neutron stars, which cannot be probed by experiments on Earth. New tools will be developed for understanding gravity through a synergy of gravitational wave observations by LIGO, and the anticipated electromagnetic signals that will be detected by ground and space-based telescopes observing from the radio to the hard gamma-ray bands. The group will develop new codes for modeling binary neutron stars and binary black hole-neutron stars with the aid of supercomputers. Such theoretical work is crucial for the successful interpretation of and the extraction of fundamental physics from existing and future observations of compact binary systems. The award will support the training, education and further career development of students in STEM fields, including minorities and women. The award will enable the development of the Computation and Mathematics Program for incoming Arizona Science Students (COMPASS) initiative, which will bridge and smooth the high school-to-college transition for students, and facilitate the success and retention of underrepresented minorities in Physics, Astronomy and other scientific fields. The specific projects have a two-fold goal: a) advance our understanding of strong field, relativistic gravity, nuclear physics and theoretical astrophysics; b) facilitate the detection and physical interpretation of gravitational waves and their possible electromagnetic counterparts. A substantial part of the effort will focus on the investigation of the inspiral and merger of compact binaries (binary neutron stars, binary black hole-neutron stars) and their gravitational wave and electromagnetic signatures. Methods will be developed for utilizing these observable signatures to extract information about fundamental physics, in particular about the nature of gravity and nuclear physics above the nuclear saturation density. More specifically, codes that run on supercomputers will be developed to solve the equations of a scalar-tensor theory of gravity with future application to binary black hole-neutron stars in order to develop techniques that test whether there are any scalar-field induced deviations from Einstein gravity that can be triggered by either charge (dark, electric or magnetic) or by magnetic fields, and to test the equivalence principle in this regime for the first time. Using existing codes, methods will be developed for probing the unknown thermal part of the equation of state at nuclear densities by using the gravitational wave and electromagnetic signatures from binary neutron star mergers. The proposed studies are extremely timely in light of the recent detection of gravitational waves by the LIGO and Virgo collaborations not only as generated by binary black holes, but also as generated by compact binaries with at least one neutron star. The project will benefit the interpretation and detection of gravitational waves and their electromagnetic counterparts not only by current and upcoming gravitational wave detectors and telescopes, but also by future ones. The proposed research will be accomplished via large-scale supercomputer simulations accompanied by analytic modeling.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.