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

AST-0707725艾森斯坦这个项目将使用斯隆数字巡天计划(SDSS)中一个专门针对发光早期类型星系的样本，以前所未有的精度探测星系的大尺度关联。这将改进现有的对重子声振荡(BaO)和宇宙物质密度的测量。在大爆炸后的头100万年中传播的声波，在宇宙微波背景(CMB)的各向异性和今天的物质集群中留下了独特的特征。这些包络在星系的关联中创造了一个尖锐的特征，其规模可以与来自CMB各向异性数据的信息相结合，以对宇宙的曲率和暗能量施加强烈的约束。SDSS发光红星系(LRG)样本是研究BAO和其他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，应该会带来重大改进，也许会将先前结果的误差条减半。宇宙膨胀率的加速是现代宇宙学的核心问题之一，对物理学构成了深刻的挑战。这项工作的观测和理论部分都将对未来星系红移测量的设计和暗能量实验的组合产生直接影响。首席调查员还将继续邀请几名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.