Cosmology through correlations

多亏了创新仪器收集的数据，我们现在有了宇宙学中一些最基本问题的答案。一个相对简单的6参数模型描述了宇宙在最大尺度上的结构和演化；在较小的尺度上，星系和星系团所在的暗物质晕的增长也得到了很好的理解。普朗克卫星为估计宇宙参数设定了黄金标准；它现在正在结束它的分析，它已经证实了过去20年左右发展起来的标准范式。那么宇宙学将何去何从呢？我们仍然需要从基本力的角度来确定为什么宇宙是这样的，也就是说，基本的宇宙模型是从哪里来的，这个模型为什么仍然不完整，以及它与高能物理理论有什么关系。其次，暗物质晕内星系的形成和演化非常复杂，因此我们并不真正知道宇宙的基本组成部分是如何形成和演化的。为了在这两个方向上取得进展，我们必须更深入地研究宇宙学。一组相互关联的工具利用相关性从大型调查中梳理出额外的信息。这包括对覆盖广泛波长范围的深河外数据集的一点（所谓的“P(D)”）和两点（即功率谱）统计的仔细研究。此外，宇宙微波背景和其他结构示踪剂之间的相关性为约束宇宙模型提供了强大的途径-宇宙红外和无线电背景，引力透镜，星系团和星系团中的散射效应。正是通过这些相关研究，宇宙学将朝着与基础物理学直接联系的方向发展——既揭示了标准宇宙学模型与基础物理理论之间的关系，又理解了复杂的重子物理如何在暗物质势下塑造星系的特性

Thanks to data gathered with innovative instrumentation, we now have the answers to some of the most fundamental questions in cosmology.  A relatively simple 6-parameter model describes the structure and evolution of the Universe on the largest scales; on smaller scales, the growth of dark matter halos, which host galaxies and galaxy clusters, is also well understood. The Planck satellite has set the gold-standard for estimating cosmological parameters; it is now wrapping up its analysis, which has confirmed the standard paradigm developed in the last 20 years or so. So where does cosmology go from here? We still need to determine WHY the Universe is the way it is, in terms of fundamental forces, i.e. where the basic cosmological model came from, how the model might still be incomplete, and how it relates to high-energy physics theories. Secondly, the formation and evolution of galaxies within dark matter halos is shrouded in complexity, so that we don't really know HOW the basic building blocks of the Universe form and evolve. To make progress in these two directions, we must dig deeper into cosmological studies. A set of inter-related tools utilises correlations to tease out additional information from large surveys. This includes careful investigations of one-point (so-called "P(D)") and two-point (i.e. power spectra) statistics of deep extragalactic data sets covering a wide range of wavelengths. Additionally, correlations between the cosmic microwave background and other tracers of structure offer powerful avenues for constraining cosmological models - the cosmic infrared and radio backgrounds, gravitational lensing, galaxy clustering and scattering effects in galaxy clusters. It is through these correlation studies that cosmology will advance towards direct connection with underlying physics - both to reveal the relationship between the standard cosmological model and underlying physical theories, and to understand how complex baryonic physics shapes the properties of galaxies within dark matter potentials.**