Probing gravity with redshift surveys

通过红移测量探测重力

• 批准号: 0907836
• 负责人: Martin White
• 金额: $ 28.43万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0907836&HistoricalAwards=false
• 关键词: Probing; gravity; redshift; surveys

Dr White will use analytical modeling, informed by a series of large, high precision N-body simulations, to better understand dark energy and the growth of structure in the cosmos. When their distances are estimated from their redshifts, galaxies on large scales appear to be more strongly clumped along the line of sight than in the tangential direction. This 'redshift distortion' depends on both the gravitational attraction between the galaxies and the effect of dark energy in accelerating the cosmic expansion. In General Relativity, the redshift distortion depends on the same combination of cosmological parameters as does weak gravitational lensing, but in other theories the two dependences differ. Dr White will use different underlying theories of gravity to run cosmological N-body simulations, then 'observe' these, to explore how redshift distortions can best be used in testing alternatives to General Relativity. He and his team will also develop a perturbation theory to follow galaxy clustering into a mildly nonlinear regime, where the velocity perturbations are no longer strictly proportional to the density fluctuations. The project will address outstanding issues in the interpretation of surveys, the modeling of redshift space distortions, and the connection between galaxies and dark matter.A graduate student will be trained through participating in the research. Tests of General Relativity have broad implications throughout physics and astronomy. Dr White will continue his public outreach talks and popular articles on cosmology, and supply educational information on public web sites.

白色博士将使用分析建模，通过一系列大型，高精度的N体模拟，以更好地了解暗能量和宇宙结构的增长。 当从它们的红移估计它们的距离时，大尺度上的星系似乎在视线上比在切向上更强烈地聚集在沿着。 这种“红移失真”既取决于星系之间的引力吸引，也取决于暗能量加速宇宙膨胀的作用。 在广义相对论中，红移失真与弱引力透镜一样依赖于宇宙学参数的组合，但在其他理论中，这两种依赖性不同。 白色博士将使用不同的引力基础理论来运行宇宙学N体模拟，然后“观察”这些，以探索如何最好地利用红移扭曲来测试广义相对论的替代方案。 他和他的团队还将开发一种微扰理论，以跟踪星系集群进入轻度非线性状态，其中速度微扰不再严格与密度波动成比例。 该项目将解决在解释调查，红移空间扭曲的建模，以及星系和暗物质之间的联系的突出问题。 广义相对论的检验在物理学和天文学中具有广泛的意义。 白色博士将继续他的公共推广讲座和流行的宇宙学文章，并在公共网站上提供教育信息。