New probes of cosmological initial conditions and dark matter properties

丹尼尔格林博士被授予美国国家科学基金会天文学和天体物理学博士后奖学金，在芝加哥大学开展研究和教育项目。大约四分之一的宇宙由一种未知成分组成，天体物理学家称之为“暗物质”。因为这种暗物质无处不在，对宇宙有着深远的影响，物理学家试图了解它的本质，并最终寻找它的真实身份。该研究员将进行一项理论研究，解决两种不寻常的暗物质（DM）候选者：极轻轴子（ELA）和无菌中微子。ELA是由弦理论、λ冷暗物质理论的问题以及非零中微子质量所驱动的。该研究员将用观测数据测试这些新的DM候选者，将这些想法与已建立的CMB各向异性实验计划和光谱畸变前沿联系起来，并更好地将原子物理学与热化时代联系起来。该研究员将测试重子分数的均匀性，提高对非高斯估计量的理解，并对早期宇宙物理学产生影响。这个项目将产生关于宇宙成分及其波动的知识。这个项目更广泛的影响包括一个重要的教育组成部分。该研究员将为芝加哥服务不足地区的老年人开展一项新的外展工作，这些地区终身学习的机会很少。该研究员将与芝加哥地区老龄化机构的老年中心合作，创建、管理和展示一系列新的天文学/宇宙学课程，每年将为200多名老年人提供课程。课程将是免费的，由年轻科学家讲授，并将吸引多种学习方式。这项工作的主要目标是向缺乏服务的芝加哥老年人介绍天文学/宇宙学的现代研究。

Dr. Daniel Grin is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the University of Chicago. About one quarter of the Universe consists of an unknown constituent that astrophysicists have given the term "dark matter." Because this dark matter is all around us and has a profound effect upon the Universe, physicists seek to understand its nature and ultimately seek its true identity.The Fellow will conduct a theoretic study that addresses two unusual dark matter (DM) candidates: an extremely light axion (ELA) and a sterile neutrino. The ELA is motivated by string theory, the sterile neutrino by problems with Lambda Cold Dark Matter theory and by the non-zero neutrino mass. The Fellow will test these new DM candidates with observables, connect these ideas to the established CMB anisotropy experimental program and the spectral distortion frontier, and better connect atomic physics to the thermalization epoch. The Fellow will test homogeneity of the baryon fraction and improve understanding of non-Gaussian estimators with implications for early universe physics. This project will produce knowledge about the constituents of the universe and their fluctuations.The broader impacts of this project include a significant educational component. The Fellow will undertake a new outreach effort for senior citizens in underserved areas of Chicago, where opportunities for lifelong learning are few. The Fellow will create, manage, and present a new series of astronomy/cosmology classes in cooperation with senior centers of the Chicago Area Agency on Aging, reaching more than about 200 seniors a year. Classes will be free, taught by young scientists, and will appeal to many learning styles. The major objective of this work is to introduce modern research in astronomy/cosmology to underserved Chicago senior citizens.