Dynamical, Strong-Field Gravity

该奖项的研究目标集中在理解爱因斯坦广义相对论的强场机制。这包括广义相对论的天体物理学和理论方面。在天体物理方面，主要工作是对双黑洞、黑洞-中子星星和双中子星星碰撞的数值模拟。这对于2015年LIGO探测到两个黑洞碰撞的新兴引力波天文学领域至关重要。该领域发展的速度令人惊叹，2017年首次引力波探测到双中子星星碰撞，伴随着大量观测天文学家对电磁频谱后果的深入研究。需要这些事件的数值模型来帮助检测，并且对于破译所发生事件的细节至关重要。在理论方面，关于极端情况下时空的性质，还有许多悬而未决的问题。一个例子是黑洞的行为，它的旋转速度接近爱因斯坦理论所允许的最大速度：有人认为这种黑洞的视界可能会表现出某种形式的湍流动力学，而这个奖项的一个目标就是调查这些说法。这些项目的实施将涉及研究生、本科生和博士后研究员。他们将接受培训，做领先的科学研究，成为物理学的相应领域的知识，并擅长高性能计算和数值方法。这些技能对许多职业来说都是无价的，因此也将有利于那些随后希望在迈阿密以外从事职业的学生和博士后的进一步发展。将进行的引力波源建模项目的具体列表是（1）使用二元黑洞合并后残余黑洞的准正常振铃特性来测试广义相对论，特别是黑洞的独特性，（2）使用黑洞合并观测来约束某些修改的引力理论，（3）开发黑洞的外来紧凑物体替代物的模型，以允许具体预测它们的合并波形如何不同于二元黑洞的合并波形，从而检测，约束或排除此类模型，（4）模拟含中子星双星合并过程中的潮汐和耗散效应。为了解决近极值克尔黑洞中的湍流问题，该小组将继续开发分析和数值工具，以研究这种黑洞在扰动理论中的二级扰动;这个奖项反映了美国国家科学基金会的法定使命，并且通过使用基金会的知识价值和更广泛的影响审查标准。

The research goals of this award are focused on understanding the strong-field regime of Einstein's theory of general relativity. This encompasses both astrophysical and theoretical aspects of general relativity. On the astrophysical side, the main effort is the numerical simulation of binary black hole, black hole-neutron star and binary neutron star collisions. This is critical for the nascent field of gravitational wave astronomy that began in 2015 with LIGO's detection of the collision of two black holes. The speed at which the field is advancing is breathtaking, with the first gravitational wave detection of a binary neutron star collision in 2017, accompanied by intense study of the aftermath across the electromagnetic spectrum by a large community of observational astronomers. Numerical models of such events are needed to aid in detection, and are crucial to decipher details of what happened. On the theoretical side, there are many outstanding questions about the nature of spacetime in extreme situations. One example is the behavior of black holes that rotate close to the maximum rate theoretically allowed by Einstein's theory : there have been suggestions that the horizons of such black holes could exhibit some form of turbulent dynamics, and one goal of this award is to investigate those claims. The pursuit of these projects will involve graduate students, undergraduates and postdoctoral fellows. They will be trained to do leading scientific research, become knowledgeable in corresponding areas of physics, and adept in high-performance computing and numerical methods. These skills are invaluable to many professions, and would thus also benefit and further the development of those students and postdocs that subsequently wish to pursue careers outside academia.A specific list of gravitational wave source modeling projects that will be pursued are (1) using properties of the quasi-normal ringdown of the remnant black hole following a binary black hole merger to test general relativity, in particular the uniqueness properties of black holes, (2) constraining certain modified gravity theories using black hole merger observations, (3) developing models of exotic compact object alternatives to black holes to allow concrete predictions of how their merger waveforms differ from those of binary black holes, and hence detect, constrain or rule out such models, and (4) modeling tidal and dissipative effects in the merger of binaries containing neutron stars. To address the problem of turbulence in near-extremal Kerr black holes, the group will continue development of analytical and numerical tools to study perturbations of such black holes to second order in perturbation theory; the outcome of this will guide whether a full numerical code adapted to the problem warrants development.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.