New probes of cosmological initial conditions and dark matter properties

Daniel Grin博士被授予NSF天文学和天体物理学博士后奖学金，在芝加哥大学开展一项研究和教育计划。宇宙的四分之一是由天体物理学家给出的术语“暗物质”的未知成分组成的。由于这种暗物质无处不在，对宇宙有着深远的影响，物理学家们试图了解它的本质，并最终寻找它的真实身份。这位科学家将进行一项理论研究，以解决两种不寻常的暗物质(DM)候选者：极轻轴子(ELA)和不育中微子。ELA是由弦理论、兰姆达冷暗物质理论的问题和非零中微子质量所驱动的不育中微子。这位研究员将用可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各向异性实验程序和光谱失真前沿联系起来，并更好地将原子物理与热化时代联系起来。这位研究员将测试重子分数的均匀性，并改进对非高斯估计值的理解，这对早期宇宙物理有意义。这个项目将产生关于宇宙组成及其波动的知识。这个项目的更广泛的影响包括一个重要的教育组成部分。这位研究员将在芝加哥服务不足的地区为老年人开展一项新的外展工作，那里终身学习的机会很少。这位研究员将与芝加哥地区老龄机构的高级中心合作，创建、管理和推出一系列新的天文学/宇宙学课程，每年接触到大约200多名老年人。课程将是免费的，由年轻的科学家授课，并将吸引许多学习方式。这项工作的主要目标是向服务不足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.