Relativistic Gravitation and Astrophysics

NSF的LIGO天文台最近探测到引力波，天文学家探测到超大质量黑洞附近的恒星和气体运动，例如银河系中心的那个黑洞，这为在时空扭曲极端的领域测试爱因斯坦的理论打开了可能性。然而，为了测试爱因斯坦的伟大理论，了解它对真实测量的实际预测是至关重要的。该项目继续进行一项研究计划，以提供爱因斯坦理论的抽象之美和复杂数学与现实世界之间的具体联系，在现实世界中，物理学家和天文学家进行测量。这些联系是通过以实用和可用的形式找到方程的近似但准确的解来建立的。这项研究的结果将被引力波天文台的数据专家用来使用新检测到的信号来更好地测试广义相对论，并将被天文学家用来探索广义相对论如何影响复杂系统，如绕着超大质量黑洞运行的恒星，或涉及从黑洞到系外行星的物体的三体系统。爱因斯坦的理论是一个吸引公众的话题，国际和平研究所将继续就与这项研究相关的主题进行公开演讲，将爱因斯坦的思想带给更广泛的社区。具体地说，这个项目将有助于地面引力波观测站，如LIGO-Virgo网络，测试广义相对论的能力，通过计算双星系统的运动方程，以及发射的引力波形，正如一个重要的替代理论，称为爱因斯坦-以太引力，在所谓的后牛顿近似中预测的高精度。它将以一种适用于LIGO-Virgo数据分析方法的格式提供该理论预测的准确波形。要解决的另一个重要问题是，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度，从而导致对发出的引力信号的可观测调制。该项目还扩展了PI最近在将爱因斯坦理论的影响纳入三体系统动力学方面的工作，例如存在第三个天体的恒星-系外行星系统，或者中心有超大质量黑洞的银河系核心的双星黑洞系统。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。

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.