Theoretical Studies in Gravitation and Astrophysics

这项研究涉及到广义相对论、引力辐射的产生、相对论流体力学、磁流体力学和恒星动力学等几个问题。连接不同理论主题的一条共同线索是引力，特别是相对论引力的关键作用。紧凑的物体（如黑洞和中子星）提供了主要的论坛，强引力场中的物质动力学是一个主要的主题。正在研究的一些课题包括：双星中子星和黑洞的启发和合并、双星引力波的产生和其他有前途的天体物理引力辐射源、引力坍缩、旋转中子星和超大质量恒星的稳定性以及不稳定恒星的最终命运，以及现在在星系和类星体的核心观察到的超大质量黑洞的形成。这些主题大多代表了理论物理中长期存在的基本问题，需要大规模的计算来解决。因此，该方法涉及并行机器上的大规模计算，以及分析建模。许多数值计算使用了UIUC国家超级计算应用中心（NCSA）最先进的计算资源。它们包括初始值和演化计算，并处理包含黑洞的真空时空以及包含现实物质源的时空。这项研究将广义相对论和天体物理学联系起来。这些结果对天文观测具有重要意义，包括那些计划用于引力波干涉仪的观测，如LIGO和LISA。相当一部分的努力致力于教育，培训和支持博士后学生和UIUC的本科生研究经验（REU）团队在计算天体物理学和相对论。这些学生与PI合作进行大部分研究。PI的每个学生在大规模计算和科学可视化以及理论物理和天体物理学的几个不同领域接受的培训，为他们在广泛的科学和技术领域从事职业生涯做好了准备。正在开发的计算机算法和数字代码对其他研究计算物理学和天体物理学的小组很有用。PI和他的团队的研究和推广活动有助于促进计算机和可视化工具在各级教育中的使用，以及公众对引力物理学和天体物理学中一些最新和最令人兴奋的发展的认识。

This reseach spans several problems involving general relativity, the generation of gravitational radiation, relativistic hydrodynamics, magnetohydrodynamics, and stellar dynamics. A common thread uniting the different theoretical topics is the crucial role of gravitation, especially relativistic gravitation. Compact objects (e.g., black holes and neutron stars) provide the principal forum, and the dynamics of matter in a strong gravitational field is a major theme. Some of the topics under investigation include the inspiral and coalescence of binary neutron stars and black holes, the generation of gravitational waves from binaries and other promising astrophysical sources of gravitational radiation, gravitational collapse, the stability of rotating neutron stars and supermassive stars and the final fate of unstable stars, and the formation of supermassive black holes now observed in the cores of galaxies and quasars. Most of these topics represent long-standing, fundamental problems in theoretical physics requiring large-scale computation for solution. Hence the approach involves large-scale computations on parallel machines, as well as analytical modeling. Many of the numerical calculations employ the state-of-the-art computational resources of the UIUC's National Center for Supercomputing Applications (NCSA). They comprise both initial value and evolution computations and treat vacuum spacetimes containing black holes as well as spacetimes containing realistic matter sources. The research bridges the fields of general relativity and astrophysics. The results have important implications for astronomical observations,including those planned for gravitational wave interferometers, such as LIGO and LISA.An appreciable portion of the effort is devoted to the education, training and support of postdoctoral students and a Research Experiences for Undergraduates (REU) team at UIUC in computational astrophysics and relativity. These students collaborate with the PI on the majority of research. The training that each of the PI's students receives in large-scale computations and scientific visualization, as well as in several different areas of theoretical physics and astrophysics, prepares them to pursue professional careers in a broad range of scientific and technical fields. The computer algorithms and numerical codes that are being developed are useful to other groups working in computational physics and astrophysics. The research and outreach activities of the PI and his group help promote the use of computers and visualization tools at all levels of education, as well as the public awareness of some the latest and most exciting developments in gravitation physics and astrophysics.