Dark Energy Dichotomies: Observational signatures of matter and gravity based theories.

AST-0607018 Bean一个基本的难题是，观测到的宇宙加速膨胀是否需要对引力理论（爱因斯坦的广义相对论）进行修改，或者是由于一种新型物质（暗能量）的额外能量密度。 这项研究计划将面对这种二分法，并建立一个补充的观测策略和精确的理论描述，以区分竞争的暗能量机制。 通过建立各种修正引力理论的线性和非线性微扰演化，以及聚集暗能量，这项研究将显示各种统计测量是否以及如何区分各种选择。 这将显示当前的数据是否足以完成任务，并通过使用模拟数据集指导未来的调查。研究包括学生培训，与弦理论家和引力物理学家的跨学科互动，以及与公众沟通的各种途径。

AST-0607018BeanA fundamental conundrum exists as to whether the observed accelerating expansion of the Universe requires a modification to the theory of gravity (Einstein's General Relativity), or is due to the additional energy density of a novel type of matter (dark energy). This research program will confront this dichotomy, and establish a complement of observational strategies and precise theoretical descriptions to differentiate the competing dark energy mechanisms. By establishing the linear and non-linear perturbation evolution for various modified gravity theories, and for clustering dark energy, this study will show if, and how, various statistical measures can distinguish between various choices. This will show whether current data are adequate to the task, and guide future surveys by using simulated datasets.The research includes student training, cross-disciplinary interactions with string theorists and gravitational physicists, and various avenues for communicating with the general public.