Measuring Cosmological Parameters in an Imperfect Universe

探测器、空间和计算机技术的进步引发了来自正在进行和即将进行的实验的高质量宇宙学数据的雪崩。然而，目前和即将到来的宇宙学参数测量的准确性受到现实世界令人头疼的问题的限制，如参数简并、微波前景、星系偏差和一长串可能的系统误差。因此，为了充分利用大量新的重大数据，对精确宇宙学的新的更高水平的雄心必须与我们对这些模糊且往往令人不快的问题的理解的相应改善相匹配。本建议的目的是：将最近发展的一些技术应用于当前可用的数据集，以解决一系列这样的现实世界问题。建议的工作有以下主要目标：利用宇宙微波背景辐射场的测量结果、大尺度结构调查和最近的SNIa调查，1.计算所有相关的宇宙学约束对下列十个宇宙学参数的联合约束：重子密度、冷暗物质密度、质量中微子密度、真空能量的贡献、再电离光学深度、空间曲率k、标量涨落的谱指数、重力波的谱指数、原始涨落幅度、和重力波的相对幅度，并研究这些结果对于不同输入数据集问题的稳健性。比较重叠的CMB实验，以评估系统问题、相对校准误差和与频率相关的前景污染的程度，将一致的数据集合并到单个更大的前景清理图中，并计算其具有不相关误差条的功率谱。为了使用新的Schleel，Davis&Finkbeiner消光图和一种基于矩阵的分析技术，以统一的方式重新分析一些关键的星系红移调查，该技术允许精确计算窗函数，包括所谓的积分约束，以及产生具有不相关误差条的功率谱。这项分析还将包括使用红移空间扭曲的依赖于尺度的随机偏差的复杂性。该项目的资金由NSF银河系外天文和宇宙学计划(AST/EXC)提供。

TegmarkAST-0071213Progress in detector, space and computer technology has triggered an avalanche of high-qualitycosmological data from ongoing and upcoming experiments. However, the accuracy of present and upcoming measurements of cosmological parameters is limited by real-world headaches such as parameter degeneracies, microwave foregrounds, galaxy bias, and a long list of possible systematic errors. To take full advantage of the avalanche of great new data, the new higher level of ambition for precision cosmology must therefore be matched by a corresponding improvement in our understanding of these murky and often unpleasant issues. This is the purpose of the present proposal: to apply a number of recently developed techniques to currently available data sets to address a range of such real-world issues.The proposed work has the following main objectives: using the results of measurements of the Cosmic Microwave Background radiation field, Large Scale Structure surveys, and the recent SNIa surveys,:1. To compute joint constraints of all relevant cosmological constraints on the following ten cosmological parameters : Baryon density, Cold dark matter density , Massive neutrino density , Contribution from vacuum energy , Reionization optical depth, Spatial curvature k , Spectral index of scalar fluctuations, Spectral index of gravity waves, Primordial fluctuation amplitude, and the Relative amplitude of gravity waves, and to study the robustness of these results with respect to problems with the various input data sets.2. To compare overlapping CMB experiments to assess the levels of systematic problems, relative calibration errors and frequency-dependent foreground contamination, to combine consistent data sets into a single larger foreground-cleaned map and to compute its power spectrum with uncorrelated error bars.3. To reanalyze a number of key galaxy redshift surveys in a uniform way using the new Schlegel,Davis & Finkbeiner extinction maps and a matrix-based analysis technique that allows anexact calculation of window functions, including the so-called integral constraint, as well asthe production of a power spectrum with uncorrelated error bars. This analysis will alsoinclude the complications of scale-dependent stochastic bias, using redshift-space distortions.Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***