General Relativistic Simulations of Binary Compact Objects

使用移动穿孔方法，现在有可能通过多个轨道、合并和最终黑洞的环形衰变来进化致密目标双星。主要任务已经变成了准确地对不同的物理问题进行建模。我们将使用这种方法来探索更现实的情况。特别是，我们计划解决几个关键的物理问题，例如：(I)中子星自转在中子星双星演化中有多重要？(Ii)我们如何才能最好地连接一个非常长的后牛顿螺旋内波形和一个从致密物体双星获得的数值波形？(Iii)后牛顿波形最高可信任的频率，以及该频率如何依赖于自转和质量比？(Iv)如果我们使用更真实的初始数据和更少的人造“垃圾”辐射，我们能得到明显更好的波形吗？NSF的LIGO引力波探测器是世界上许多旨在直接探测和测量引力波的新设施之一。这些波将来自各种天体物理来源，并将打开一扇通往宇宙的新窗口。这些探测器最有希望的来源之一是致密天体双星(即包含黑洞或中子星的系统)的逆旋和合并。随着这两个天体越来越近，需要对爱因斯坦方程进行完全非线性的数值模拟，以预测螺旋内合并和随后合并的最后部分。我们的模拟产生的引力波形将对其他科学小组有价值，如LIGO合作。计划中的研究将涉及FAU的至少一名研究生和耶拿大学的一名博士后。因此，计划中的研究将对参与其中的学生和博士后产生教育效益。他们不仅将学习与该项目相关的科学知识，还将更广泛地了解超级计算机编程和数据管理。

Using the moving puncture approach, it is now possible to evolve compact-object binaries through many orbits, merger and the ringdown of the final black hole. The main task has become to accurately model different physical problems. We will use this method to explore more physically realistic situations. In particular, we plan to address several key physics issues such as: (i) How important is neutron star spin in the evolution of neutron star binaries? (ii) How can we best join a very long post-Newtonian in-spiral waveform and a numerically obtained waveform from a compact object binary? (iii) Up to which frequency can post-Newtonian waveforms be trusted, and how does this frequency depend on spins and mass ratios? (iv) Can we get significantly better waveforms if we use more realistic initial data with less artificial "junk" radiation? The NSF's LIGO gravitational wave detector is among a number of new facilities all over the world which are designed to directly detect and measure gravitational waves. These waves will come from a variety of astrophysical sources and will open a new window to the universe. One of the most promising sources for these detectors are the in-spirals and mergers of compact-object binaries (i.e., systems containing black holes or neutron stars). As the two objects get close, fully non-linear numerical simulations of the Einstein equations are required to make predictions about the final part of the in-spiral and subsequent merger. The gravitational waveforms produced by our simulations will be valuable for other scientific groups such as the LIGO collaboration. The planned research will involve at least one graduate student at FAU and one postdoc at the University of Jena. Thus the planned research will have educational benefits for the students and postdocs involved. They will not only learn about the science related to this project, but also more broadly about programming supercomputers and data management.