Problems in Gravitation (Physics)

万有引力问题（物理学）

• 批准号: 9310083
• 负责人: Richard Matzner
• 金额: $ 73.6万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9310083&HistoricalAwards=false
• 关键词: Problems; Gravitation; Physics

9310083 Matzner A study will be performed of relativistic systems, especially as applied to the interaction of black holes, cosmology and the formation of the elements in cosmology, and to tests of General Relativity in near Earth experiments. The black hole and cosmological studies will be primarily numerical. In order to predict the expected gravitational wave signals in the LIGO detector, the orbital dynamics and merger of astrophysical black holes will be numerically simulated. A number of techniques, including adaptive multigrid finite differencing will be employed (Adaptive multigrid permits arbitrarily fine resolution at important points in the simulation). Obtaining useful signal predictions from black hole evolution requires extremely high accuracy in the numerical development. The codes will be implemented on massively parallel computers (such as the Thinking Machine CM 5) which have the memory and the computing power to handle these large scale simulations. The end product will be a catalog of wave forms, relevant to producing appropriate detection algorithms for LIGO. This waveform catalog in particular will allow extraction of binary orbital information as well as of the black hole characteristics before and after merger of the two holes. Cosmological studies will concentrate on the formation of elements in the early universe, particularly in maintaining and upgrading existing computer codes at Texas. Areas to be emphasized will be newly measured nuclear reaction rates, the extension of nuclear reaction chains to include heavier elements, the refinement of numerical techniques in these codes, and the porti ng of the nucleosynthesis codes to large parallel machines. Other aspects of cosmology to be studied include the formation of structure in the early universe and the implementation of computer codes accurately describing it; and the statistics of gravitational lensing, (multiple images of distant QSOs caused by an intervening cluster of galaxies), and models of gravitational lenses. ***

9310083 Matzner将对相对论系统进行研究，特别是应用于黑洞相互作用、宇宙学和宇宙学中元素的形成，以及近地实验中的广义相对论测试。黑洞和宇宙学研究将主要是数值研究。为了预测LIGO探测器中预期的引力波信号，将对天体物理黑洞的轨道动力学和合并进行数值模拟。将采用许多技术，包括自适应多重网格有限差分(自适应多重网格允许在模拟中的重要点处具有任意精细的分辨率)。从黑洞演化中获得有用的信号预测需要在数值开发中具有极高的精度。这些代码将在大规模并行计算机(如Think Machine CM 5)上实现，这些计算机具有处理这些大规模模拟的内存和计算能力。最终产品将是一个波形目录，与为LIGO生产适当的检测算法相关。该波形目录尤其允许提取二进制轨道信息以及两个黑洞合并前后的黑洞特征。宇宙学研究将集中在早期宇宙中元素的形成，特别是在维护和更新德克萨斯州现有的计算机代码方面。重点将是新测量的核反应速率，将核反应链扩展到包括更重的元素，这些程序中数值技术的改进，以及核合成程序向大型并行机器的移植。宇宙学要研究的其他方面包括早期宇宙结构的形成和准确描述它的计算机代码的实施；引力透镜的统计数据(由中间星系团造成的遥远类星体的多幅图像)，以及引力透镜的模型。***