Research on Gravitational Waves and Compact Binaries

引力波和致密双星研究

基本信息

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

项目摘要

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.

在过去的几年中，Ligo和处女座探测器合并了中子星和恒星质量黑洞的令人兴奋的观察结果开辟了引力波天文学时代。这些事件揭示了新的天体物理学，包括确认创建重元素的过程，并发现一类新的重型恒星质量黑洞，并正在提供一般相对论理论的新颖测试。他们还预示着极端质量比率（EMRIS）的最终引力波观测，其中恒星质量的黑洞或中子恒星螺旋螺旋成为超级质量的黑洞，例如现在已知存在于几乎所有大型星系的中心。这些超级质量的黑洞被密集的恒星簇包围，经常将紧凑的星星（例如中子星或恒星质量黑洞）捕获到高度偏心的轨道中。当这些紧凑的恒星轨道时，它们会辐射重力波，导致轨道腐烂，而紧凑的物体最终被超质量黑洞吞噬。发射的引力辐射可能与未来的空间重力波检测器Lisa可观察到。该奖项资助的理论工作将改善对高度紧凑的合并二进制文件的预期信号的预测。从这种EMRI的引力波检测将提供重力的独特强场测试并探测黑洞的性质。为了追求这一努力，将制定黑洞扰动理论中新技术的发展，并将进行引力自我强制方法，以及编写相关的高级计算机代码。将研究扰动理论和自力计算的高度精度结果，以发现野后二元运动和相关引力波发射的牛顿后膨胀中的高阶术语。极端质量比率的扰动理论和自我强制性发现，牛顿后重叠地区的支持，并加强了更广泛的努力，以推动牛顿后理论提高高级订单，并为合并二进制的有效模型提供校准。 PI的组最初使用标量字段模型将自力量计算扩展到Kerr背景上的通用运动，主要重点使这些计算更有效。新的自我力量技术将与示意元素代码相结合，以建立偏心Emris的长期灵感模型。这项工作的某些部分将与都柏林大学学院大学的几位前学生以及同事进行外部合作。数值和分析结果以及某些计算机代码将在线提供。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响标准，被认为值得通过评估来获得支持。