Cosmology from Surveys

我们似乎生活在一个奇异的宇宙中。最近的测量结果强烈支持一个“和谐”模型，其中宇宙是平坦的，包含大约4%的重子，21%的冷暗物质和75%的暗能量。暗能量的概念是爱因斯坦宇宙常数（λ）的变体。这种“λ +冷暗物质”的范式及其扩展提出了关于宇宙起源的基本问题。宇宙似乎开始于一个快速膨胀的时期，最终冷却成一个黑暗的世界，在这个世界中，第一个物体形成并重新电离了宇宙。沿着暗能量，这些过程构成了这项提议的研究基础。我们方案的一个独特之处是它汇集了星系巡天、引力透镜、射电巡天分析和宇宙微波背景辐射方面的专门知识。该计划还连接了UCL宇宙学和仪器团队。自2004年成立以来，宇宙学小组的主要重点一直是暗能量，在暗能量调查（DES）和欧空局拟议的欧几里得卫星中发挥了重要的参与和领导作用。随着2009年招聘了两名新的工作人员，我们已经扩展到宇宙微波背景（利用普朗克卫星）和无线电测量（例如LOFAR）的研究领域。因此，我们现在对现代宇宙学有了更广泛的了解。我们将估计暗能量的性质，约束非常早期宇宙的物理学，研究宇宙经历再电离时的相变，并可能首次测量中微子的质量。拟议的计划分为四个主题，从低到高红移列出：主题1涵盖测光红移巡天的宇宙学，主题2侧重于这些巡天的宇宙切变，主题3探讨射电巡天主要用于研究再电离时代，主题4着眼于早期宇宙的基本问题，借助普朗克数据。UCL的宇宙学团队非常适合这个项目。这四位申请人在分析大型星系调查，设计弱透镜和再电离时代的调查以及从CMB研究早期宇宙等领域非常有经验，我们最有希望发现在非常高的能量尺度下运行的物理学指纹。拟议的计划将使我们能够保持和加强我们在国际项目中的领导作用，并培养和激励年轻一代的宇宙学家。

It seems we live in a bizarre Universe. Recent measurements strongly favour a 'concordance' model in which the Universe is flat and contains approximately 4% baryons, 21% Cold Dark Matter and 75% Dark Energy .The concept of Dark Energy is a variant on Einstein's cosmological constant (Lambda). This 'Lambda+ Cold Dark Matter' paradigm and its extensions pose fundamental questions about the origins of the Universe. The Universe appears to have begun with a period of rapid inflation and eventually cooled into a dark world in which the first objects formed and re-ionized the Universe. Along with Dark Energy, these processes form the basis for research of this proposal. A unique feature of our Programme is that it brings together expertise in galaxy surveys, gravitational lensing, radio survey analysis and the CMB. The Programme also connects the UCL Cosmology and Instrumentation Teams. Since its foundation in 2004 the main focus of the Cosmology Team has been Dark Energy with heavy involvement and leadership roles in both the Dark Energy Survey (DES) and in the proposed ESA Euclid satellite. With the recruitment of two new members of staff in 2009 we have branched into the research areas of the Cosmic Microwave Background (utilizing the Planck satellite) and Radio Surveys (e.g. LOFAR). Therefore we have now a much broader coverage of modern Cosmology. We will estimate the properties of Dark Energy, constrain the physics of the very early Universe, study the phase change as the universe underwent Re-ionization, and potentially measure the mass of the neutrino for the first time. The proposed Programme is divided into four Themes, listed from low to high redshift: Theme 1 covers Cosmology from Photometric Redshift Surveys, Theme 2 is focused on Cosmic Shear from these surveys, Theme 3 explores Radio Surveys mainly for studying the Epoch of Re-ionization, and Theme 4 looks at the fundamental problems of the Early Universe, with the aid of data from Planck. The Cosmology Team at UCL is well placed for this project. The four applicants are very experienced in the fields of analyzing large galaxy surveys, designing surveys for weak lensing and for the Epoch of Re-ionization, and studying the early universe from the CMB, our best hope for uncovering fingerprints of the Physics operating at very high energy scales. The proposed Programme would allow us to maintain and enhance our leadership roles in international projects, and to train and inspire a young generation of Cosmologists.