Measuring Cosmological Parameters in an Imperfect Universe

测量不完美宇宙中的宇宙学参数

• 批准号: 0071213
• 负责人: Max Tegmark
• 金额: $ 24.41万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0071213&HistoricalAwards=false
• 关键词: Measuring; Cosmological; Parameters; Imperfect; Universe

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).***

探测器、空间和计算机技术的进步已经从正在进行和即将进行的实验中引发了大量高质量的宇宙学数据。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难题的限制，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数据，我们对精确宇宙学的更高层次的雄心必须与我们对这些模糊的、往往令人不快的问题的理解的相应改进相匹配。这就是本建议的目的：将一些最近开发的技术应用于目前可用的数据集，以解决一系列这样的现实问题。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；计算所有相关宇宙学约束对以下10个宇宙学参数的联合约束：重子密度、冷暗物质密度、大质量中微子密度、真空能量贡献、再电离光学深度、空间曲率k、标量涨落谱指数、引力波谱指数、原始涨落幅值和引力波相对幅值，并研究这些结果对于不同输入数据集问题的鲁棒性。比较重叠的CMB实验，以评估系统问题的程度、相对校准误差和频率相关的前景污染，将一致的数据集组合成一个更大的前景清理地图，并计算其功率谱与不相关的误差条。使用新的Schlegel，Davis & Finkbeiner消光图和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，这种分析技术允许精确计算窗口函数，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。该分析还将包括尺度相关随机偏差的复杂性，使用红移空间扭曲。本项目由美国国家科学基金会星系外天文学和宇宙学项目（AST/EXC）资助