Research on Gravitational Waves and Compact Binaries

引力波和致密双星研究

• 批准号: 1806447
• 负责人: Charles Evans
• 金额: $ 16.5万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806447&HistoricalAwards=false
• 关键词: Research; Gravitational; Waves; Compact; Binaries

The exciting observations by the LIGO and Virgo detectors of merging neutron stars and stellar-mass black holes over the past several years have opened up the era of gravitational wave astronomy. These events have revealed new astrophysics, including confirming the process through which heavy elements are created and discovering a new class of heavy stellar-mass black holes, and are providing novel tests of general relativity theory. They also herald eventual gravitational wave observations of extreme-mass-ratio inspirals (EMRIs), where a stellar-mass black hole or neutron star spirals into a supermassive black hole, such as those now known to exist in the center of virtually all large galaxies. Surrounded by dense star clusters, these supermassive black holes will frequently capture compact stars (e.g., neutrons stars or stellar mass black holes) into highly eccentric orbits. As these compact stars orbit, they radiate gravitational waves, causing the orbit to decay and the compact object to eventually be swallowed by the supermassive black hole. The emitted gravitational radiation is potentially observable with LISA, the future space-based gravitational wave detector. The theoretical work funded by this award will provide improved predictions of the expected signals from highly-eccentric compact merging binaries. Detection of gravitational waves from such EMRIs will provide unique strong field tests of gravity and probe the nature of black holes.To pursue this effort, development of new techniques in black hole perturbation theory and gravitational self-force methods will be made, along with writing associated advanced computer codes. High precision results from perturbation theory and self-force calculations will be studied to uncover high-order terms in the post-Newtonian expansion of eccentric binary motion and associated gravitational wave emission. Perturbation theory and self-force findings in the extreme-mass-ratio, post-Newtonian overlap region support and reinforce broader efforts to advance post-Newtonian theory to higher orders and provide calibrations for effective-one-body models of merging binaries. The PI's group is extending self-force calculations to generic motion on Kerr backgrounds, using a scalar field model initially, with primary focus to make these computations more efficient. New self-force techniques will be combined with osculating elements codes to build long-term inspiral models for eccentric EMRIs. Some parts of this work will be conducted in external collaboration with several former students and with colleagues at University College Dublin. Numerical and analytic results, as well as some computer codes, will be made available online.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.

在过去的几年里，LIGO和Virgo探测器对合并中子星和恒星质量黑洞的激动人心的观测开启了引力波天文学的时代。这些事件揭示了新的天体物理学，包括证实了重元素产生的过程，发现了一类新的重恒星质量黑洞，并为广义相对论提供了新的检验。它们也预示着最终会观测到极端质量比吸气（EMRIs）的引力波，在那里，一个恒星质量黑洞或中子星螺旋变成一个超大质量黑洞，就像现在已知的存在于几乎所有大型星系中心的黑洞一样。这些超大质量黑洞被密集的星团包围，经常会将致密恒星（例如，中子星或恒星质量黑洞）捕获到高度偏心的轨道上。当这些致密恒星绕轨道运行时，它们会辐射引力波，导致轨道衰减，致密物体最终被超大质量黑洞吞噬。发射的引力辐射可能会被LISA观测到，LISA是未来的天基引力波探测器。由该奖项资助的理论工作将提供对高偏心致密合并双星预期信号的改进预测。从这样的emri中探测引力波将提供独特的引力强场测试，并探测黑洞的本质。为了实现这一目标，将开发黑洞摄动理论和引力自作用力方法的新技术，并编写相关的高级计算机代码。将研究来自摄动理论和自力计算的高精度结果，以揭示偏心双星运动和相关引力波发射的后牛顿膨胀中的高阶项。摄动理论和自力在极端质量比、后牛顿重叠区域的发现支持并加强了将后牛顿理论推进到更高阶的更广泛的努力，并为合并双星的有效一体模型提供了校准。PI的团队正在将自力计算扩展到Kerr背景上的一般运动，最初使用标量场模型，主要关注使这些计算更有效。新的自作用力技术将与模拟元件编码相结合，建立偏心EMRIs的长期激励模型。这项工作的某些部分将与几名以前的学生和都柏林大学学院的同事进行外部合作。数值和分析结果，以及一些计算机代码，将在网上提供。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

Repeated faint quasinormal bursts in extreme-mass-ratio inspiral waveforms: Evidence from frequency-domain scalar self-force calculations on generic Kerr orbits

• DOI: 10.1103/physrevd.100.064008
• 发表时间: 2019-05
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Zachary Nasipak;Thomas Osburn;C. Evans

Eccentric-orbit extreme-mass-ratio-inspiral radiation. II. 1PN correction to leading-logarithm and subleading-logarithm flux sequences and the entire perturbative 4PN flux

• DOI: 10.1103/physrevd.102.104006
• 发表时间: 2020-09
• 期刊: arXiv: General Relativity and Quantum Cosmology
• 作者: Christopher Munna;C. Evans

Trumpet initial data for boosted black holes

吹响增强型黑洞的初始数据

• DOI: 10.1103/physrevd.98.044014
• 发表时间: 2018
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Slinker, Kyle;Evans, Charles R.;Hannam, Mark
• 通讯作者: Hannam, Mark

Resonant self-force effects in extreme-mass-ratio binaries: A scalar model

极端质量比双星中的共振自力效应：标量模型

• DOI: 10.1103/physrevd.104.084011
• 发表时间: 2021
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Nasipak, Zachary;Evans, Charles R.
• 通讯作者: Evans, Charles R.

Eccentric-orbit extreme-mass-ratio-inspiral radiation: Analytic forms of leading-logarithm and subleading-logarithm flux terms at high PN orders

偏心轨道极端质量比吸气辐射：高 PN 阶下前对数和次前对数通量项的解析形式

• DOI: 10.1103/physrevd.100.104060
• 发表时间: 2019
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Munna, Christopher;Evans, Charles R.
• 通讯作者: Evans, Charles R.