WOU-MMA: Gravitational Radiation and Relativistic Astrophysics

WOU-MMA：引力辐射和相对论天体物理学

• 批准号: 2309211
• 负责人: Mark Scheel
• 金额: $ 107.55万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309211&HistoricalAwards=false
• 关键词: WOU; MMA; Gravitational; Radiation; Relativistic

This award supports research in relativity and relativistic astrophysics, and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. Since 2019, NSF's Laser Interferometer Gravitational-Wave Observatory (LIGO) has been regularly detecting gravitational waves (GWs) (ripples in space and time) emitted by the collision of compact objects that are billions of light-years from Earth. Most of these objects have been black holes, others have been neutron stars. From the GWs, scientists can measure properties (locations, masses, spins) of the objects and learn about how they might have formed and how they warp space and time as they collide; for neutron stars, the collision also produces gamma-rays and other electromagnetic radiation, and together with the GWs this teaches scientists how matter behaves at ultra-high densities and how some chemical elements were formed. But these studies require comparing the detected GWs with detailed predictions of the waves. The predictions are made using the equations of General Relativity, written down by Einstein in 1915 but unsolvable (for colliding compact objects) until about 2005 with the development of advanced methods and powerful supercomputers. This project supports theoretical work designed to underpin and improve LIGO's ability to extract from observed GWs the rich information that the waves carry, and to improve the interpretation of LIGO events with electromagnetic counterparts. This includes the improvement and use of the Spectral Einstein Code (SpEC), currently the most accurate computer code for solving Einstein's equations for black hole binaries. SpEC will be used to carry out numerical solutions of black-hole collisions to further develop a public catalog of GW predictions for the purpose of analyzing LIGO data. In addition, a next-generation public computer code SpECTRE, under development, will be used to predict GWs from two colliding neutron stars, from a black hole colliding with a neutron star, and from supernova explosions. This program will also serve as a training ground for young physicists and astrophysicists. The group members will reach out to the general public through lectures, interactive web pages, and YouTube videos.By combining analytical techniques and numerical simulations with the Spectral Einstein Code (SpEC), the team will: (i) improved gravitational waveforms for Binary Black Holes (BBH) will be generated for use in LIGO data analysis in poorly-explored regions of the BBH parameter space, and will be used to produce surrogate models that are improved in accuracy, parameter-space coverage, and included physics (e.g. eccentricity, gravitational memory); and (ii) the dynamical behavior of highly curved spacetime will be explored via analytic, perturbative, and numerical approaches, which will include studies of quasinormal mode excitations and nonlinearities in ringdowns, and investigations of beyond-Einstein theories of gravitation and testing them using LIGO observations.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，它解决了NSF“宇宙之窗”大构想的优先领域。自2019年以来，美国国家科学基金会的激光干涉仪引力波天文台（LIGO）一直在定期探测距离地球数十亿光年的致密物体碰撞发出的引力波（空间和时间的涟漪）。这些物体中的大多数是黑洞，其他的是中子星。从GWs中，科学家可以测量物体的属性（位置、质量、自旋），并了解它们可能是如何形成的，以及它们在碰撞时如何扭曲空间和时间；对于中子星来说，碰撞也会产生伽马射线和其他电磁辐射，与GWs一起，这告诉科学家物质在超高密度下的行为以及一些化学元素是如何形成的。但是这些研究需要将探测到的gw与对引力波的详细预测进行比较。这些预测是根据广义相对论做出的，广义相对论是爱因斯坦在1915年写下的，但直到2005年，随着先进方法和强大超级计算机的发展，才得以解决（对于致密物体的碰撞）。该项目支持理论工作，旨在巩固和提高LIGO从观测到的GWs中提取丰富信息的能力，并通过电磁对口改进对LIGO事件的解释。这包括改进和使用光谱爱因斯坦代码（SpEC），这是目前解决爱因斯坦黑洞双星方程的最精确的计算机代码。SpEC将用于执行黑洞碰撞的数值解，以进一步开发GW预测的公共目录，用于分析LIGO数据。此外，正在开发的下一代公共计算机代码SpECTRE将用于预测两颗中子星碰撞、黑洞与中子星碰撞以及超新星爆炸产生的gw。该项目还将成为年轻物理学家和天体物理学家的培训基地。小组成员将通过讲座、互动网页和YouTube视频与公众接触。通过将分析技术和数值模拟与光谱爱因斯坦代码（SpEC）相结合，该团队将：(i)将生成改进的双黑洞（BBH）引力波形，用于LIGO在BBH参数空间中未被探索的区域的数据分析，并将用于生成替代模型，这些模型在精度、参数空间覆盖范围和包括物理（例如偏心、引力记忆）方面有所提高；（ii）高度弯曲时空的动力学行为将通过解析、微扰和数值方法进行探索，其中将包括准正态模式激发和环振中的非线性研究，以及超越爱因斯坦引力理论的研究，并使用LIGO观测对其进行测试。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。