Luminous Red Galaxies in the Sloan Digital Sky Survey: Baryon Acoustic Oscillations and the Composition of the Universe

该项目将使用斯隆数字巡天（SDSS）中一个特殊的发光早期型星系样本，以前所未有的精度探测星系之间的大规模相关性。这将改进现有的重子声学振荡（BAO）和宇宙物质密度的测量。在大爆炸后的第一个一百万年里传播的声波，在宇宙微波背景（CMB）的各向异性和今天的物质聚集中留下了独特的特征。这些BAO在星系之间的相关性中创造了一个鲜明的特征，它们的尺度可以与来自CMB各向异性数据的信息相结合，从而对宇宙的曲率和暗能量施加强有力的约束。SDSS发光红星系（LRG）样本是研究BAO等大尺度结构的最佳数据集。将这些数据与新的理论见解结合起来应该会带来显著的改进，也许可以将早期结果的误差条减半。宇宙膨胀速度的加速是现代宇宙学的核心问题之一，对物理学提出了深刻的挑战。这项工作的观测和理论部分都将对未来星系红移调查的设计和暗能量实验的组合产生直接影响。首席研究员还将继续让研究生和本科生参与这项研究。

AST-0707725EisensteinThis project will use a specially-targeted sample of luminous early-type galaxies in the Sloan Digital Sky Survey (SDSS) to probe the large-scale correlations of galaxies with unprecedented accuracy. This will refine existing measurements of the baryon acoustic oscillations (BAO) and the matter density of the Universe. Sound waves that propagate in the first million years after the Big Bang imprint distinctive features into the anisotropies of the cosmic microwave background (CMB) and the clustering of matter today. These BAO create a sharp feature in the correlation of galaxies whose scale can be combined with information from CMB anisotropy data to place strong constraints on the curvature of the Universe and on dark energy. The SDSS Luminous Red Galaxy (LRG) sample is the best dataset by a wide margin for studying the BAO and other aspects of large-scale structure. Coupling these data with new theoretical insights should lead to significant improvements, perhaps halving the error bars on earlier results.The acceleration of the expansion rate of the Universe is one of the central problems in modern cosmology and poses a deep challenge to physics. Both the observational and the theoretical parts of this work will have a direct impact on the design of future galaxy redshift surveys, and on the portfolio of dark energy experiments. The principal investigator will also continue to engage several students, both graduate and undergraduate, in this research.