Testing General Relativity with Galaxy Surveys

在过去的十年里，宇宙学取得了巨大的进步，我们现在有了一个高度可预测的宇宙结构出现的模型，它借鉴了高能物理、引力理论和天体物理学的一套丰富的想法。然而，这个模型需要一个非常令人惊讶的因素，那就是宇宙的加速扩张。这种加速提出了当今物理科学中最深刻的问题，即使是最平淡无奇的解释也要求存在一种具有奇异物理性质的新成分(“暗能量”)。更极端的选择包括额外的空间维度或宇宙尺度上的广义相对论的崩溃。幸运的是，星系的运动使我们能够探测暗能量并测试广义相对论。将这一认识转化为精密工具是该项目的目标。该项目旨在发展大尺度结构可以提供的洞察力，作为暗能量和修正引力的探测器。通过将最先进的建模和新的分析方法与从红移调查中积累的大量新数据集相结合，可以利用红移空间扭曲同时测量宇宙结构的增长率和宇宙几何。研究人员将验证并将植根于扰动理论的模型应用于现有近期数据集的最具约束性的子集，以生成对该领域当前状态的一致荟萃分析。

Cosmology has made tremendous advances in the last decade, and we now have a highly predictive model for the emergence of structure in the Universe, which draws upon a rich set of ideas from high energy physics, gravitation theory, and astrophysics. However, this model requires one very surprising ingredient, an accelerating expansion of the Universe. This acceleration poses the most profound question in physical science today with even the most prosaic explanations demanding the existence of a new constituent ("dark energy") with exotic physical properties. More extreme alternatives include extra spatial dimensions or a breakdown of General Relativity on cosmological scales. Luckily, the motion of galaxies allows us to probe dark energy and to test General Relativity. Turning this realization into a precision tool is the goal of this project.The project aims to develop the insight that large-scale structure can provide as a probe of dark energy and modified gravity. By combining state-of-the-art modeling and new analysis methods with the massive new data sets being accumulated from redshift surveys, it is possible to simultaneously measure the growth rate of cosmic structure and the cosmological geometry using redshift-space distortions. The investigators will validate and apply models rooted in perturbation theory to the most constraining subsets of existing near-future data sets to generate a consistent meta-analysis of the current state of the field.