Dynamical and Strong-Gravity Effects from Black-Hole Binaries

黑洞双星的动力和强重力效应

• 批准号: 2011784
• 负责人: David Nichols
• 金额: $ 21万
• 依托单位: University of Virginia Main Campus
• 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 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2011784&HistoricalAwards=false
• 关键词: Dynamical; Strong; Gravity; Effects; Black

The NSF's Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo detector have now observed gravitational waves from tens of pairs of merging black holes and neutron stars. These remarkable observations have opened up a new field of gravitational-wave astrophysics, and they are allowing the predictions of Einstein's theory of relativity to be tested in new ways for these dynamic and strongly gravitating binaries. Much remains to be learned from these novel observations. Through a better understanding of the predictions of Einstein's theory and through more precise calculations of the emitted gravitational waves, more of the scientific potential of these observations will be tapped. This project, therefore, outlines a research program to use a combination of foundational computations, as well as analytical and numerical modeling of black holes and neutron stars, to aid in extracting insights from gravitational-wave observations. Many of the calculations will be carried out by graduate students, who will be trained in techniques that are useful in physics research and other quantitative areas. A final component of the project involves the development of visualizations that are intended for a broad audience of non-scientists, which aim to make the generation of gravitational waves more intuitive and accessible.More specifically, the research goals of this project will be to make advances in gravitational physics on two fronts: (i) to investigate and compute the part of the gravitational waveform that is strongly constrained by the symmetries and conserved quantities of isolated radiating systems, and (ii) to compute gravitational waveforms from a range of black-hole binaries that can be used to look for deviations from relativity because of the presence of matter or the modification of the underlying gravitational theory. The main goals of direction (i) are first, to compute gravitational waveforms associated with gravitational-wave memory effects that can be evaluated rapidly; second, to understand discrepancies between two commonly used definitions of angular momentum in asymptotically flat spacetimes; and third, to compute generalized notions of memory effects in these spacetimes. For direction (ii), there are three different objectives: for the first, investigating the influence of dense distributions of matter on the gravitational waveforms from black-hole binaries with mass ratios that differ greatly from one; for the second, to explore how modifications to general relativity affect the gravitational-wave memory effect; and for the last, approximating the gravitational waveform in modified gravity theories using a combination of perturbative expansions. The outreach aims of this project revolve around creating visualizations of the warped spacetime of binaries radiating gravitational waves. The visualizations will highlight the physical stretching and squeezing effects of gravitational waves and illustrate how gravitational waves are generated. Animations of these visualizations will be posted online and could also be used as pedagogical tools.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的激光干涉仪引力波天文台（LIGO）和处女座探测器现在已经观测到几十对黑洞和中子星合并产生的引力波。这些引人注目的观测为引力波天体物理学开辟了一个新的领域，它们使爱因斯坦相对论的预言能够以新的方式对这些动态的、强引力的双星进行检验。从这些新颖的观察中，我们还可以学到很多东西。通过更好地理解爱因斯坦理论的预测，通过对发射的引力波进行更精确的计算，这些观测的更多科学潜力将被挖掘出来。因此，该项目概述了一项研究计划，将基础计算与黑洞和中子星的分析和数值模拟相结合，以帮助从引力波观测中提取见解。许多计算将由研究生进行，他们将接受在物理研究和其他定量领域有用的技术训练。该项目的最后一个组成部分涉及为非科学家的广大受众开发可视化，其目的是使引力波的产生更加直观和易于理解。更具体地说，这个项目的研究目标将是在两个方面取得引力物理学的进展：(i)研究和计算受孤立辐射系统的对称性和守恒量强烈约束的引力波形部分，以及（ii）计算一系列黑洞双星的引力波形，这些波形可用于寻找由于物质的存在或潜在引力理论的修改而偏离相对论。方向(i)的主要目标是，首先，计算与引力波记忆效应相关的引力波波形，可以快速评估；第二，了解渐近平坦时空中角动量的两种常用定义之间的差异；第三，计算这些时空中记忆效应的广义概念。对于方向（ii），有三个不同的目标：第一，研究物质密度分布对质量比相差很大的黑洞双星的引力波形的影响；第二，探讨广义相对论的修正如何影响引力波记忆效应；最后，用微扰展开的组合来近似修正重力理论中的重力波形。这个项目的扩展目标围绕着创建双星辐射引力波的扭曲时空的可视化。可视化将突出引力波的物理拉伸和挤压效应，并说明引力波是如何产生的。这些可视化的动画将在网上发布，也可以用作教学工具。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

Persistent gravitational wave observables: Curve deviation in asymptotically flat spacetimes

• DOI: 10.1103/physrevd.105.024056
• 发表时间: 2021-09
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Alexander M. Grant;D. Nichols

Measuring the dark matter environments of black hole binaries with gravitational waves

• DOI: 10.1103/physrevd.105.043009
• 发表时间: 2022-02-14
• 期刊: PHYSICAL REVIEW D
• 影响因子: 5
• 作者: Coogan, Adam;Bertone, Gianfranco;Nichols, David A.
• 通讯作者: Nichols, David A.

Outlook for detecting the gravitational-wave displacement and spin memory effects with current and future gravitational-wave detectors

• DOI: 10.1103/physrevd.107.064056
• 发表时间: 2022-10
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Alexander M. Grant;D. Nichols

Erratum: Outlook for detecting the gravitational-wave displacement and spin memory effects with current and future gravitational-wave detectors [Phys. Rev. D 107, 064056 (2023)]

勘误表：用当前和未来的引力波探测器探测引力波位移和自旋记忆效应的展望[Phys.

• DOI: 10.1103/physrevd.108.029901
• 发表时间: 2023
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Grant, Alexander M.;Nichols, David A.
• 通讯作者: Nichols, David A.

Brans-Dicke theory in Bondi-Sachs form: Asymptotically flat solutions, asymptotic symmetries, and gravitational-wave memory effects

• DOI: 10.1103/physrevd.103.104026
• 发表时间: 2020-07
• 期刊: arXiv: General Relativity and Quantum Cosmology
• 作者: S. Tahura;D. Nichols;A. Saffer;L. Stein;Kent Yagi