CAREER: Research and Education in Gravitational-Wave Science

2015年，美国国家科学基金会资助的激光干涉仪引力波天文台（LIGO）探测到引力波，证实了爱因斯坦广义相对论的最后预言，开启了观测天文学和基础物理学的新时代。LIGO及其国际合作伙伴未来的观测将发现更多正在合并的黑洞对。这些观测将帮助我们了解这些系统是如何形成的，并将让我们在这些合并黑洞产生的超强引力区域中测试广义相对论。这里资助的工作主要涉及：(i)提高我们模拟LIGO将从黑洞合并中探测到的信号的能力；（ii）发展技术，以模拟和探测引力波信号的一个组成部分，这些组成部分可以揭示引力的非线性性质、超新星喷射的物质和能量，或经历近距离飞过的致密恒星的动力学；（三）探索下一代引力波实验可能实现的科学目标。这项工作的教育组成部分包括：(i)在一所地区性公立大学培训本科和硕士学位学生，服务于各种社会经济背景；（ii）开发并提供用于教授LIGO科学的教学材料和实践工具包；（三）通过讲座、外展展览和继续发展“时空之声”网站（该网站通过与声波类比来解释引力波科学）吸引更广泛的公众。这项工作的科学目标集中在(i)改进具有椭圆（偏心）轨道的合并双星系统模型和（ii）引力波记忆效应。椭圆双星：LIGO目前有许多信号模型来分析圆轨道双星，但用于椭圆双星的信号模型很少。该小组将开发新的信号模型来处理偏心轨道，并研究参数估计和测试广义相对论的含义。如果偏心率出现在LIGO信号中，它将对致密天体双星形成模型产生影响，并限制广义相对论的可能偏差（如果忽略偏心率，广义相对论可能存在偏差）。记忆效应：记忆效应是指引力波信号的非振荡成分。它是由引力双体散射、超新星中的抛射物质或中微子以及黑洞合并过程中的非线性相互作用产生的。这项研究将改进现有的记忆效应模型。它还将使用LIGO数据开发、测试和执行对内存爆发的搜索。这将扩大LIGO研究的信号类别，并可能提供一种检验广义相对论的新方法。

The detections of gravitational waves in 2015 by the NSF-funded Laser Interferometer Gravitational-wave Observatory (LIGO) have confirmed the last prediction of Einstein's theory of general relativity and opened up a new era in observational astronomy and fundamental physics. Future observations by LIGO and its international partners will discover many more merging black hole pairs. These observations will help us understand how these systems formed and will let us test general relativity in the ultra-strong gravity region produced by these coalescing black holes. The work funded here is primarily concerned with: (i) improving our ability to model the signals LIGO will detect from black hole mergers; (ii) developing techniques to model and detect a component of gravitational-wave signals that can shed light on the nonlinear nature of gravity, the matter and energy ejected by supernovae, or the dynamics of compact stars that experience close flybys; and (iii) exploring science objectives that could be achieved by the next generation of gravitational-wave experiments. The educational components of this work include: (i) training undergraduate and master's degree students at a regional public university serving a wide range of socio-economic backgrounds; (ii) developing and making available instructional materials and hands-on kits that teach LIGO science; (iii) engaging the broader public through lectures, outreach exhibits, and the continued development of the "Sounds of Spacetime" website (which explains gravitational-wave science via an analogy with sound waves). The science objectives of this work are focused on (i) improving models of merging binary systems with elliptical (eccentric) orbits and (ii) the gravitational-wave memory effect. Elliptical binaries: LIGO currently has many signal models to analyze circular-orbit binaries, but few for elliptical binaries. The group will develop new signal models to handle eccentric orbits and investigate the implications for parameter estimation and testing general relativity. If present in LIGO signals, eccentricity will have implications for compact object binary formation models and constraining possible deviations from general relativity (which could be biased if eccentricity is neglected). Memory effect: The memory effect refers to a non-oscillatory component of the gravitational-wave signal. It is produced by gravitational two-body scattering, ejected matter or neutrinos in supernovae, and nonlinear interactions during black hole mergers. The effort will improve existing models of the memory effect. It will also develop, test, and execute a search for memory bursts using LIGO data. This will broaden the class of signals that LIGO investigates and could provide a new way to test general relativity.