Simulations of Black-Hole Binaries with Moving Punctures

该奖项支持了一项研究计划，该计划旨在为不同质量比和自转的天体物理黑洞双星的合并建模。主要的重点是开发和应用数值相对论和微扰方法的新工具，以帮助目前和未来的引力波探测工作，并解决当前天体物理感兴趣的问题。最近的突破使数值相对论进入了应用于天体物理和引力波数据分析的新的黄金时代。特别是，罗切斯特理工学院(RIT)的数值相对论小组(以及独立的NASA戈达德小组)开发了一种被称为“移动-穿孔”方法的新技术，能够稳定地将黑洞双星从螺旋阶段(至少几个轨道)演化到合并阶段和衰变阶段。数值相对论研究计划的主要科学目标是调查：(I)关于高度非线性相互作用细节的一些重要的公开物理问题，(Ii)引力辐射的产生，以及(Iii)不等质量、旋转的黑洞双星的天体物理性质。为了实现这些，这项研究将解决一些重要的挑战，例如：(1)为从真实的螺旋轨道开始的模拟获得天体物理相关的初始数据，(2)探索不同质量比和自转的大参数空间，以及(3)确保多轨道模拟本身对于引力波探测和信号解释都足够准确。在计算方面，研究人员建议加强他们目前的计算框架(LazEv)，以适当地应对这些挑战。此外，从晚期全3D双星演化中提取引力辐射并用稳定而准确的2D微扰演化来演化的“Lazarus”程序将在移动穿孔方法的框架内得到扩展。最后，一个正在进行的项目将被扩展到研究一个围绕克尔黑洞运行的小型致密天体的轨道衰变。一旦探测到，引力波将打开一扇通往宇宙的新窗口。不等质量黑洞双星与随机取向的单个自旋的结合将成为地面探测器(如LIGO)和下一代天基探测器(如LISA)都能探测到的最强引力波天体物理来源之一。特别是，LIGO现在正在获取数据，它的灵敏度很有可能在未来几年内探测到来自合并黑洞的引力波。这项研究将对LIGO特别重要，因为它的目标是产生用于重力波数据分析的引力波形模板。该奖项为支持计算相对论和引力中心(CCRG)最近在RIT创建的一个新的数值相对论密集研究项目提供了重要资源。CCRG将提供一个新的研究环境，让学生接触到尖端研究和技术。这些学生将学习操作大规模并行计算机、高性能计算和代码优化、复杂三维数据的可视化以及在强引力系统中进行尖端研究的关键技能。

This award supports a research program to model the coalescence of astrophysical black-hole binaries for different mass ratios and spins. The main focus is on the development and application of novel tools for numerical relativity and perturbative methods to assist the current and future gravitational wave detection efforts and to solve problems of current astrophysical interest. Recent breakthroughs have allowed numerical relativity to enter a new golden age of applications to astrophysics and gravitational wave data analysis. In particular, the numerical relativity group at the Rochester Institute of Technology (RIT) (and independently the NASA Goddard group) has developed a new technique, known as the "moving-puncture" approach, capable of stably evolving black-hole binaries from the inspiral phase (for at least several orbits) through the merger and ring-down phases. The main scientific objectives of the numerical relativity research program are to investigate: (i) some important open questions of physical interest about the details of highly nonlinear interactions, (ii) the generation of gravitational radiation, and (iii) astrophysical properties of unequal-mass, spinning black-hole binaries. To achieve these, this research will address some important challenges such as: (1) obtaining astrophysically relevant initial data for simulations that start from a realistic inspiral orbit, (2) exploring the large parameter space for different mass ratios and spins, and (3) ensuring that the multiple-orbit simulations themselves are accurate enough for both gravitational wave detection and the interpretation of the signals. On the computational side, the investigators propose to enhance their current computational framework (LazEv) to properly address these challenges. In addition, the "Lazarus" program to extract the gravitational radiation from late-time full-3D binary evolutions and evolve it with a stable and accurate 2D perturbative evolution will be extended in the framework of the moving punctures approach. Finally, an ongoing program will be extended to study the orbital decay of a small compact object orbiting a Kerr black hole.Once detected, gravitational waves will open a new window into the universe. The coalescence of unequal-mass black-hole binaries with randomly oriented individual spins will be one of the strongest astrophysical sources of gravitational waves detectable by both ground-based detectors, such as LIGO, and the next generation of space-based detectors, such as LISA. In particular, LIGO is now taking data and its sensitivity is such that it is possible that gravitational waves from merging black holes will be detected in the next few years. This research will be of particular importance to LIGO since its goal is to produce gravitational waveform templates to be used for gravitional wave data analysis. This award provides important resources to support a new research-intensive program in numerical relativity at the Center for Computational Relativity and Gravitation (CCRG), recently created at the RIT. The CCRG will provide a new research environment in which students are exposed to cutting-edge research and technology. These students will learn critical skills in operating massively parallel computers, high performance computing and code optimization, visualization of complex 3-dimensional data, as well perform cutting edge research in strongly gravitating systems.