CAREER: Research in Strong-Field Gravity and Astrophysics

该奖项的部分资金来自《2021年美国救援计划法案》(公法117-2)。正如美国国家科学基金会的使命所说，该项目服务于国家利益，促进科学进步，并为促进国家繁荣和福祉奠定基础；特别是，该奖项将使人们能够通过将理论和多信使观测与引力波相结合来研究广义相对论中的紧凑双星系统和修正引力。这项工作将促进我们对碰撞中子星内部深处产生的密度和温度下的核物理的理解，这是地球上的实验无法探测到的。将开发新的工具，通过LIGO的引力波观测和地面和空间望远镜从射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了解引力。该小组将开发新的代码，在超级计算机的帮助下对双星中子星和双星黑洞-中子星进行建模。这样的理论工作对于成功地解释和从现有和未来的致密双星观测中提取基础物理是至关重要的。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，包括少数民族和妇女。该奖项将推动亚利桑那州理科新生计算和数学课程(COMPASS)计划的发展，该计划将为学生从高中过渡到大学铺平道路，并促进在物理、天文学和其他科学领域未被充分代表的少数族裔的成功和留住。这些具体项目有两个目标：a)增进我们对强场、相对论引力、核物理和理论天体物理学的理解；b)促进对引力波及其可能的电磁对应波的探测和物理解释。很大一部分工作将集中在研究致密双星(双星中子星、双星黑洞中子星)及其引力波和电磁特征的激发和合并。将开发利用这些可观测特征提取基本物理信息的方法，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，以求解标量-张量引力理论的方程，并在未来应用于黑洞-中子星，以便开发测试是否存在由电荷(暗、电或磁场)或磁场触发的标量场引起的爱因斯坦引力偏差的技术，并首次在这种情况下测试等效原理。利用现有的代码，将开发出利用来自双中子星合并的引力波和电磁特征来探测核密度下状态方程的未知热部分的方法。鉴于LIGO和Virgo合作最近探测到的引力波，拟议的研究非常及时，不仅是由双星黑洞产生的，而且是由至少有一颗中子星的致密双星产生的。该项目不仅将有利于目前和即将使用的引力波探测器和望远镜，而且也将有利于未来的引力波及其电磁对应物的解释和探测。这项拟议的研究将通过大规模的超级计算机模拟和分析建模来完成。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 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.