Relativistic Gravitation and Astrophysics

相对论引力和天体物理学

• 批准号: 1909247
• 负责人: Clifford Will
• 金额: $ 30万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1909247&HistoricalAwards=false
• 关键词: Relativistic; Gravitation; Astrophysics

The recent detections of gravitational waves by NSF's LIGO observatories and by astronomers of the motions of stars and gas near supermassive black holes, such as the one at the center of the Milky Way, have opened the possibility of testing Einstein's theory in realms where the warping of spacetime is extreme. Yet in order to test Einstein's great theory, it is essential to know what it actually predicts for real measurements. This project continues a program of research to provide concrete links between the abstract beauty and complex mathematics of Einstein's theory and the real world where measurements are made by physicists and astronomers. These links are established by finding approximate, yet accurate solutions of the equations in forms that are practical and usable. The outcomes of this research will be used by data experts at the gravitational-wave observatories to perform better tests of general relativity using newly detected signals, and will be used by astronomers to probe how general relativity affects complex systems such as stars orbiting supermassive black holes, or three-body systems involving bodies ranging from black holes to exoplanets. Einstein's theory is a topic that fascinates the general public, and the PI will continue to give public lectures on topics related to this research, bringing understanding of Einstein's ideas to the broader community.Specifically, this project will contribute to the ability of ground-based gravitational-wave observatories such as the LIGO-Virgo network to test general relativity, by computing the equations of motion for binary star systems, along with the emitted gravitational waveforms, as predicted by an important alternative theory, known as Einstein-Aether gravity, to high accuracy in the so-called post-Newtonian approximation. It will provide accurate waveforms predicted by this theory in a format that can be adapted to LIGO-Virgo data analysis methods. Another important question that will be addressed is whether the evolution of binary orbits with general relativistic effects included leaves any residual orbital ellipticity in the final stages, leading to observable modulations of the gravitational signals emitted. The project also extends recent work of the PI on incorporating the effects of Einstein's theory into the dynamics of three-body systems, such as a star-exoplanet system in the presence of a third body, or a binary-black-hole system in a galactic core with a supermassive black hole at its center.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.

美国国家科学基金会（NSF）的LIGO天文台最近探测到引力波，天文学家在超大质量黑洞（比如银河系中心的黑洞）附近探测到恒星和气体的运动，这为在时空极端扭曲的领域测试爱因斯坦的理论提供了可能性。然而，为了验证爱因斯坦的伟大理论，有必要知道它对实际测量的实际预测。这个项目继续了一项研究计划，旨在为爱因斯坦理论的抽象之美和复杂数学与物理学家和天文学家进行测量的现实世界之间提供具体联系。这些联系是通过找到近似的、精确的、实用的形式的方程解来建立的。这项研究的结果将被引力波天文台的数据专家用来利用新探测到的信号对广义相对论进行更好的测试，并将被天文学家用来探测广义相对论如何影响复杂的系统，比如围绕超大质量黑洞运行的恒星，或者涉及从黑洞到系外行星的三体系统。爱因斯坦的理论是一个让公众着迷的话题，PI将继续就与这项研究相关的主题进行公开讲座，让更广泛的社区了解爱因斯坦的思想。具体来说，这个项目将有助于地面引力波观测站，如LIGO-Virgo网络，通过计算双星系统的运动方程，以及发射的引力波，来测试广义相对论的能力，正如一个重要的替代理论所预测的那样，被称为爱因斯坦-以太引力，在所谓的后牛顿近似中达到高精度。它将以一种可以适应LIGO-Virgo数据分析方法的格式提供由该理论预测的精确波形。另一个要解决的重要问题是，包含广义相对论效应的双星轨道的演化是否会在最后阶段留下任何剩余的轨道椭圆性，从而导致发射的引力信号的可观测调制。该项目还扩展了PI最近的工作，即将爱因斯坦理论的影响纳入三体系统的动力学中，例如存在第三个物体的恒星-系外行星系统，或者位于银河系核心的双黑洞系统，其中心有一个超大质量黑洞。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。

项目成果

Residual eccentricity of inspiralling orbits at the gravitational-wave detection threshold: Accurate estimates using post-Newtonian theory

引力波探测阈值处螺旋轨道的残余偏心率：使用后牛顿理论的准确估计

• DOI: 10.1103/physrevd.104.104023
• 发表时间: 2021
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Tucker, Alexandria;Will, Clifford M.
• 通讯作者: Will, Clifford M.

A Stability Timescale for Nonhierarchical Three-body Systems

• DOI: 10.3847/1538-4357/acd782
• 发表时间: 2023-01
• 期刊: The Astrophysical Journal
• 作者: Eric Zhang;S. Naoz;C. Will

Higher-order effects in the dynamics of hierarchical triple systems: Quadrupole-squared terms

• DOI: 10.1103/physrevd.103.063003
• 发表时间: 2020-11
• 期刊: Physical Review D
• 影响因子: 5
• 作者: C. Will

Modified geodesic equations of motion for compact bodies in alternative theories gravity

替代引力理论中紧致体运动的修正测地线方程

• DOI: 10.1103/physrevd.106.064021
• 发表时间: 2022
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Taherasghari, Fatemeh;Will, Clifford M.
• 通讯作者: Will, Clifford M.

A Hidden Friend for the Galactic Center Black Hole, Sgr A*

• DOI: 10.3847/2041-8213/ab5e3b
• 发表时间: 2019-12
• 期刊: The Astrophysical Journal Letters
• 作者: S. Naoz;C. Will;E. Ramirez-Ruiz;A. Hees;A. Ghez;T. Do