Research in Black-Hole Physics and Relativistic Astrophysics

该奖项支持相对论和相对论天体物理学的研究。这项研究的很大一部分是通过超级计算机模拟来解决爱因斯坦方程的数值问题。这项提议的研究将对我们对基础物理学的理解产生广泛的影响。像LIGO这样的实验才刚刚开始在黑洞强场范围内对广义相对论进行真正的检验。要用观察来对抗理论，人们必须能够计算出理论所预测的东西。LIGO观测到的黑洞是爱因斯坦理论预言的黑洞吗？这项研究将对天文学产生影响。包含中子星的双星系统的合并可能导致电磁和中微子信号的发射，以及引力波。这开启了以多种方式同时观察这些事件的可能性，从而更好地理解这些事件。模拟将有助于确定导致最强电磁和中微子信号的二进制的参数，以及这些信号的特征（时间标度，强度等），这些特征可能对开发检测这些信号的最佳搜索策略很重要。这项研究还将对计算科学的更广泛领域产生影响。在这里开发的计算技术可以用于解决许多其他领域的问题，包括流体动力学、气象学、地震学和天体物理学。在这些技术方面受过训练的年轻研究人员需求量很大。相对论和黑洞继续吸引着公众，并使科学得以广泛传播。调查人员制作的模拟电影将继续提供公众宣传。为了求解爱因斯坦方程，研究人员将使用一种计算技术，即伪光谱搭配，它比其他技术以更小的计算成本提供更高的精度。其中一个重点是跟踪双黑洞系统的合并和合并，并计算这些过程发出的引力波形。研究的第二个重点是研究包含一颗中子星和一个黑洞或两颗中子星的双星系统的聚结和合并。研究人员将在模拟中加入更真实的微物理描述，如核物质的状态方程、中微子效应和磁场。研究人员还将为计算天体物理学开发一种新的代码，该代码旨在利用即将到来的百亿亿次机器，这是当前代码无法做到的。这个新代码将基于不连续Galerkin方法和基于任务的并行性。它不仅将为数值相对论提供革命性的能力，而且还将为计算天体物理学中的许多问题提供革命性的能力。

This award supports research in relativity and relativistic astrophysics. A large component of the research is aimed at the numerical solution of Einstein's equations by supercomputer simulations. The proposed research will have a broad impact on our understanding of fundamental physics. The first real tests of general relativity in the strong field regime of black holes are just beginning to occur with experiments like LIGO. To confront theory with observation, one must be able to calculate what the theory predicts. Are the black holes that LIGO observes the black holes predicted by Einstein's theory? The research will have an impact on astronomy. Mergers of binary systems containing neutron stars may lead to the emission of electromagnetic and neutrino signals, as well as gravitational waves. This opens the possibility of concurrently observing such events in multiple ways leading to greater understanding of such events. The simulations will help determine the parameters of such binaries that lead to the strongest electromagnetic and neutrino signals, and the characteristics of these signals (timescale, strength, etc.) that may be important in developing optimal search strategies for detecting these signals. The research will also have an impact on the broader area of computational science. The computational techniques to be developed here can be used to solve problems in many other areas, including fluid dynamics, meteorology, seismology, and astrophysics. Young researchers trained in these techniques are in great demand. Relativity and black holes continue to fascinate the public and allow science to be communicated broadly. Movies of simulations produced by the investigators will continue to provide public outreach.To solve Einstein's equations, the investigators will use a computational technique, pseudospectral collocation, that delivers high accuracy with a much smaller computational cost than other techniques. One focus is to track the coalescence and merger of binary black hole systems and to calculate the gravitational waveform emitted by such processes. A second focus of the research is to study the coalescence and merger of binary systems containing a neutron star and a black hole, or two neutron stars. The investigators will include ever more realistic descriptions of the microphysics in the simulations, such as the equation of state of nuclear matter, neutrino effects, and magnetic fields. The investigators will also develop a new code for computational astrophysics that is designed to take advantage of upcoming exascale machines in a way that current codes cannot. This new code will be based on discontinuous Galerkin methods and task-based parallelism. It will provide transformative capabilities not only for numerical relativity, but for many problems in computational astrophysics.