Testing Gravity with Galaxy Clusters

用星系团测试重力

• 批准号: 1976266
• 金额: --
• 依托单位: University of Portsmouth
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1976266
• 关键词: Testing; Gravity; Galaxy; Clusters

Clusters of galaxies are the largest gravitationally bound objects in the Universe and provide a unique laboratory for testing theories of gravity. Our team has pioneered the technique of comparing different tracers of the cluster gravitational potential to place tight constraints on possible deviations from General Relativity (GR) on cosmological scales. This thesis will build upon our previous work in three new areas. First, we will expand the quality and quantity of cluster data available through our proprietary access to the Dark Energy Survey (DES; www.darkenergysurvey.org) and extended X-ray catalogues. We will also explore the use of public KIDS lensing data. Secondly, we will add new cluster tracers (beyond lensing and X-ray), including Sunyaev-Zel'dovich (SZ) pressure maps of DES clusters and velocity dispersion profiles from on-going galaxy redshift surveys. Finally, we will explore a wider range of modified gravity models (e.g. emergent gravity, beyond horndeski, extended tensor-scalar) and continue to improve our N-body simulations for such theories. We will also build better mock observations from these simulations by adding the SZ effect and individual (mock) galaxies to the dark matter halos. Together, we expect this work to improve present constraints on deviations from GR by at least an order of magnitude, providing the best evidence yet for the suitability of GR on cosmological scales (or not!). The thesis will also look beyond present data-sets to new constraints from the next generation of astronomical surveys from Euclid, LSST and 4MOST.

星系团是宇宙中最大的引力约束物体，为检验引力理论提供了独特的实验室。我们的团队开创了比较星系团引力势的不同示踪剂的技术，以严格限制宇宙学尺度上可能偏离广义相对论（GR）的情况。本论文将建立在我们以前的工作在三个新的领域。首先，我们将通过我们对暗能量调查（DES; www.darkenergysurvey.org）和扩展X射线目录的专有访问来扩展集群数据的质量和数量。我们还将探索公共KIDS透镜数据的使用。其次，我们将增加新的集群示踪剂（除了透镜和X射线），包括Sunyaev-Zel'dovich（SZ）的DES集群的压力图和正在进行的星系红移调查的速度色散剖面。最后，我们将探索更广泛的修改引力模型（例如涌现引力，超越horndeski，扩展张量标量），并继续改进我们对这些理论的N体模拟。我们还将通过将SZ效应和单个（模拟）星系添加到暗物质晕中，从这些模拟中建立更好的模拟观测。总之，我们希望这项工作能够改善目前对GR偏差的限制至少一个数量级，为GR在宇宙学尺度上的适用性提供最好的证据（或不是！）。论文还将超越目前的数据集，从欧几里得，LSST和4 MOST的下一代天文调查的新的约束。