Theoretical Studies in Gravitation and Astrophysics

引力和天体物理学的理论研究

基本信息

批准号：
2006066
负责人：
Stuart Shapiro
金额：
$ 51万
依托单位：
University of Illinois at Urbana-Champaign
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2006066&HistoricalAwards=false
关键词：
Theoretical Studies Gravitation Astrophysics

项目摘要

This award supports research in relativity and relativistic astrophysics and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. The LIGO/Virgo Scientific Collaboration has compiled an impressive list of detected gravitational wave (GW) events consisting of several dozen binary black hole (BHBH) mergers, a couple of binary neutron star (NSNS) mergers and several likely black hole--neutron star (BHNS) mergers. These detections mark the beginning of the era of GW astronomy. This research project spans several problems involving general relativity (GR), the generation of GWs, relativistic hydrodynamics, and relativistic magnetohydrodynamics. A common thread uniting the different theoretical topics is the crucial role of gravitation, especially relativistic gravitation. Compact objects (black holes, neutron stars and white dwarfs) provide the principal forum, and the dynamics of matter in a strong gravitational field is a major theme. Some of the topics for investigation include the inspiral and coalescence of compact binaries (BHBHs, NSNSs and BHNSs); the generation of GWs from merging binaries and other promising astrophysical sources, and their counterpart electromagnetic (EM) signals; gravitational collapse; the stability of rotating, relativistic stars and the evolution and final fate of unstable stars; gamma-ray burst sources (GRBs); the formation and growth of supermassive black holes (SMBHs) from the magnetorotational collapse of supermassive stars (SMSs) and other scenarios; circumbinary disks around merging binary SMBHs in the cores of galaxies and quasars; and the profiles and observable signatures of dark matter around SMBHs in galaxy cores, including the Milky Way, and the dynamical evolution of clusters containing DM, stars and SMBHs. The results have important implications for astronomical observations, including those collected by and/or planned for GW interferometers.Most of these topics represent long-standing, fundamental problems in theoretical physics requiring large-scale computation for solution. Hence the approach involves to a significant degree large-scale simulations on supercomputers, in addition to analytical modeling. The key tool will be the robust and well-tested Illinois general relativistic, magnetohydrodynamic (GRMHD) code. The simulations solve Einstein's field equations of GR for gravity coupled to the equations of relativistic MHD for the fluid and Maxwell's equations for the EM fields. These equations constitute highly nonlinear, coupled partial differential equations in 3+1 dimensions that are solved by finite-differencing. The Illinois GRMHD code employs the Baumgarte-Shapiro-Shibata-Nakamura (BSSN) technique with moving puncture gauge conditions and adaptive moving mesh refinement to solve the field equations and a high-resolution, shock capturing scheme for the MHD. The problems to be tackled comprise both initial value and evolution computations and treat vacuum spacetimes containing black holes, as well as spacetimes containing realistic matter sources, magnetic fields and both EM and neutrino radiation ("multimessenger astronomy"). The research and outreach activities supported by this grant help promote the use of computers and visualization tools at all levels of education, as well as the public awareness of some the latest and most exciting developments in gravitational physics and astrophysics.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.

该奖项支持相对论和相对论天体物理学的研究，并介绍了NSF“宇宙上的Windows”的优先领域。 LIGO/处女座的科学合作汇编了一份令人印象深刻的被检测到的引力波（GW）事件，其中包括数十个二进制黑洞（BHBH）合并，几个二进制中子星（NSN）合并和几个可能的黑洞 - 可能的黑洞 - 中子star（BHNS）合并。这些发现标志着GW天文学时代的开始。该研究项目涵盖了涉及一般相对论（GR），GWS产生，相对论流体动力学和相对论磁性水力动力学的几个问题。结合不同理论主题的一个共同线程是引力的关键作用，尤其是相对论重力。紧凑的物体（黑洞，中子星和白矮人）提供了主要论坛，在强烈的引力领域中物质的动态是一个主要主题。一些调查的主题包括紧凑型二进制文件（BHBHS，NSNS和BHNS）的灵感和合并；合并二进制文件和其他有希望的天体物理来源及其对应电磁（EM）信号的GW产生；重力崩溃；旋转，相对论恒星以及不稳定恒星的进化和最终命运的稳定性；伽马射线爆发来源（GRB）；超级质量星（SMS）和其他场景的超级质量黑洞（SMBH）的形成和生长；围绕星系和类星体核心二进制SMBH的二元SMBH围绕；以及银河系中SMBH周围的暗物质的概况和可观察的特征，包括银河系，以及包含DM，恒星和SMBH的簇的动态演变。结果对天文观察具有重要意义，包括由GW干涉仪收集和/或计划的。这些主题中的大多数代表了长期存在的理论物理学基本问题，需要大规模计算解决方案。因此，除了分析建模外，该方法在很大程度上涉及超级计算机的大规模模拟。关键工具将是伊利诺伊州一般相对论，磁性水力动力学（GRMHD）代码的强大且经过良好测试的工具。该模拟求解了重力的Einstein的GR场方程，并为EM领域的流体和麦克斯韦方程的相对论MHD方程耦合。这些方程构成了3+1维的高度非线性，耦合的部分微分方程，这些方程是通过有限差异来求解的。伊利诺伊州GRMHD代码采用了带有移动的穿刺量规条件和适应性移动网格细化的Baumgarte-Shapiro-Shibata-Nakamura（BSSN）技术，以求解现场方程，并为MHD提供高分辨率，震惊的捕获方案。要解决的问题包括初始价值和进化计算，并处理包含黑洞的真空空间，以及含有现实的物质源，磁场以及EM和中微子辐射的空间（“多中间机天文学”）。这项赠款支持的研究和外展活动有助于促进各种教育的计算机和可视化工具的使用，以及公众对引力物理学和天体物理学中一些最新，最令人兴奋的发展的认识。该奖项反映了NSF的法定任务，并通过该基金会的知识优点和广泛的影响来评估NSF的法定任务。