Galaxy Clusters and The Dark Energy

AST 0205010白色宇宙学在过去的十年中取得了巨大的进步，许多基本问题接近解决。 我们现在有了一个高度预测宇宙中大尺度结构出现的理论。正如通常的情况一样，这一理论提出了新的问题，还有几个关键问题仍有待理解。首先，宇宙中大多数物质的性质仍然是神秘的。其次，虽然我们已经知道地球物质并不主导宇宙中的能量，但我们现在相信即使是外来的“暗”物质也不起这种作用。 目前，宇宙似乎正在加速，由一种被称为“暗能量”的神秘成分驱动。幸运的是，我们正处于宇宙学观测的“黄金时代”。即将到来的观测将很快限制结构形成的初始条件和许多宇宙学参数，使我们能够解决下一个前沿问题：结构形成的时代。对结构形成的透彻理解有助于确定发展中的“宇宙网”范式的后果和对该范式内变化的约束。理解的关键是星系团。这是已知的最大的天体。它们表现出显著的规律性，但我们对它们结构的理解对我们的建模假设很敏感。 该项目将构建星系团的计算机模型，以开发和改进将这些星系团的性质与暗物质和暗能量的分布和性质联系起来的方法，从而加强我们对这种主导范式的测试。

AST 0205010WhiteCosmology has made tremendous advances in the past decade, with many fundamental questions approaching resolution. We now have a highly predictive theory for the emergence of large-scale structure in the Universe. As is often the case, this theory raises new questions, and several crucial issues still remain to be understood. First, the nature of most of the matter in the Universe remains mysterious. Second, while we have known for some time that earthly matter doesn't dominate the energy in the Universe, we now believe that not even exotic `dark' matter plays that role. At present the Universe appears to be accelerating, driven by a mysterious component dubbed "dark energy''. Luckily we are in a "golden era'' of cosmological observations. Upcoming observations will soon constrain the initial conditions for structure formation and many cosmological parameters, allowing us to address the next frontier: the era of structure formation. A thorough understanding of structure formation is instrumental in determining both the consequences of the developing 'cosmic web' paradigm and the constraints on variations within this paradigm. The key to this understanding is clusters of galaxies. These are the largest known objects. They exhibit remarkable regularity, but our understanding of their structure is sensitive to our modeling assumptions. This project will construct computer models of galaxy clusters to develop and refine methods which will relate the properties of these clusters to the distribution and nature of the dark matter and the dark energy and thus to sharpen our tests of this dominant paradigm.***