Cosmology, Theoretical and Computational Astrophysics

计算天体物理学的一个研究项目将由William Press教授和他的团队进行。要研究的主题将包括以下内容：(1)继续发展一类新的快速统计方法（由Rybicki和Press发现），将信号和数据处理中的一些以前棘手的问题减少到计算快速的问题。(2)将这些方法应用到中高红移星系的研究中，可以发现新的宇宙学信息。(3)对大尺度宇宙流真实性的若干测试，包括Ia型超新星的使用。(4)系统研究在可观测的最大尺度上测量星系相关函数（或功率谱）的新的统一方法。(5)灾难性变星作为我们银河系早期演化历史的一个指示器的可能作用。(6)在大宇宙尺度上测量质量与光的比值。(7)并行计算算法和“习惯用法”在科学计算中的应用研究。(8)可能的话，在小波基础的流体力学领域和/或经典的三维场论计算领域的大规模计算机代码的发展。Press教授和他的团队致力于宇宙学、理论天体物理学、计算物理学和天体物理学等领域的研究。在这些主题的多样性背后，存在着兴趣的中心焦点：在热大爆炸的情况下，今天宇宙的结构是由引力形成的吗？如果是这样，如何，何时，以及对宇宙的初始条件有什么影响？该小组的主要兴趣不仅在于开发与这个问题有关的新的、可测试的理论思想，而且还在于开发新的分析、统计和计算技术，这些技术能够扩展现有和未来观测数据集的能力和相关性。为此，P ress和他的同事们对快速计算方法、并行计算和新算法的开发一直很感兴趣。通常，这些理论不仅适用于引力物理学和天体物理学，还适用于更广泛的科学和工程。

A research program in computational astrophysics will be carried out by Prof. William Press and his group. Topics to be investigated will include the following: (1) Continued development of a new class of fast statistical methods (discovered by Rybicki and Press) that reduce some formerly intractable problems in signal and data processing to computationally fast problems. (2) Application of these methods to the study of galaxies at moderate to high redshifts, where new cosmological information can be discerned. (3) Several tests on the reality of large scale cosmological flows, including the use of Type Ia supernovae. (4) A systematic investigation of new and unified methods for measuring the galaxy correlation function (or power spectrum) on the very largest scales accessible to observation. (5) The possible role of cataclysmic variable stars as an indicator of the early history of evolution of our Galaxy. (6) Measurement of mass-to-light ratios on large cosmological scales. (7) A study of parallel computational algorithms and "idioms" with application to scientific computing generally. (8) Possibly, the development of large scale computer codes in the areas of hydrodynamics in wavelet basis, and/or classical three- dimensional field theory calculations. Prof. Press and his group work on a variety of topics in cosmology, theoretical astrophysics, and computational physics and astrophysics. Behind this diversity of topics, lies the central focus of interest: Given the hot big bang, did the structure in the Universe today form gravitationally? And, if so, how, when, and with what implications regarding the Universe's initial conditions? The group has a major interest not only in developing new, testable, theoretical ideas that bear on this question, but also in developing new analytical, statistical, and computational techniques that are capable of extending the power and relevance of existing and future observational data sets. Towards this end, P ress and his co-members have a continuing interest in fast computational methods, parallel computing, and the development of new algorithms. Often these have application not only to gravitational physics and astrophysics, but also to science and engineering more broadly.