Probing Inflationary Cosmology with CLASS

托马斯·埃辛格-希尔曼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，在约翰·霍普金斯大学开展一项研究和教育计划。该研究员的研究计划是用宇宙学大角度尺度测量仪(CLASS)测量宇宙微波背景(CMB)的偏振。这项拟议的研究解决了宇宙起源和性质的基本问题，并帮助天体物理学家检验关于宇宙诞生的相互竞争的理论。在2010年的天文学和天体物理十年调查中，这种测量被认为是最重要的科学任务。该项目将促进建立CMB的高灵敏度偏振图和温度图，并直接测试非常早期的高能宇宙的膨胀模型。宇宙膨胀将产生引力波背景，其水平与膨胀结束时的真空能量密度直接对应。通过寻找引力波背景在CMB偏振中的奇宇称信号，即所谓的“B模”，班级将在10^16 GeV的大统一理论(GUT)能量尺度上研究物理。相比之下，大型强子对撞机被设计成探测高达7x10^3GeV的能量。CLASS将在高海拔地点形成一个多频率天文台，在目前和计划中的地面实验中，它在针对大角度尺度的B型功率谱再电离凸起方面是独一无二的。PI将领导90 GHz级接收器的开发、调试和现场校准。这将包括设计一种新颖的焦平面结构，用于馈电喇叭耦合的过渡边缘传感器偏振器的单片阵列，以及结合他自己设计的硅粉过滤器的独特热过滤策略。该项目的更广泛影响包括一个重要的教育部分。这位研究员将与约翰·霍普金斯教育外展中心合作开展一项教育外展计划，在两年的时间里，向一个以非裔美国人为主的学区的高中生传达宇宙学方面令人兴奋的发展。随着研究的进展，这位研究员将通过音频和视频媒体、网络博客和照片来交流进展。他每月都会与一群10年级和11年级的学生见面，让学生们参与在智利的实验室和望远镜上进行的研究。随后，将通过约翰·霍普金斯大学年度物理博览会等现有方案，以及通过在万维网网站上的互动演示，扩大为这一方案编写的演示材料，以接触到更广泛的受众。这个由项目望远镜看到的天空叙事之旅将向全球广泛的观众展示该项目在宇宙学方面的结果。

Dr. Thomas Essinger-Hileman is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Johns Hopkins University. The fellow's research program is to measure the polarization of the cosmic microwave background (CMB) with the Cosmology Large Angular Scale Surveyor (CLASS). The proposed research addresses fundamental questions of the origin and nature of the Universe and helps astrophysicists test competing theories of the birth of the Universe. Such measurements were regarded a top scientific priority in the 2010 Decadal Survey of Astronomy and Astrophysics.This project will facilitate the creation of high-sensitivity polarization and temperature maps of the CMB and directly test inflationary models of the very early, energetic Universe. Cosmological inflation would produce a gravitational-wave background at a level that directly corresponds with the vacuum energy density at the end of inflation. By looking for the odd-parity signature of a gravitational-wave background in the CMB polarization, the so-called "B modes," CLASS will investigate physics on grand-unification-theory (GUT) energy scales of 10^16 GeV. In contrast, the Large Hadron Collider is designed to probe energies up to 7x10^3 GeV. CLASS will form a multi-frequency observatory at a high-altitude site, and it is unique among current and planned ground-based experiments in aiming at the reionization bump in the B-mode power spectrum at large angular scales. The PI will lead the development, commissioning, and field calibration of the 90 GHz receivers for CLASS. This will include the design of a novel focal plane architecture for monolithic arrays of feedhorn-coupled, transition-edge-sensor polarimeters, as well as unique thermal filtering strategies incorporating silicon-powder filters of his own design. The broader impacts of this project include a significant educational component. The fellow will undertake a program of educational outreach in partnership with the Johns Hopkins Center for Educational Outreach to convey exciting developments in cosmology to high school students in a predominantly African-American school district over a two-year period. As the research progresses, the fellow will communicate developments through audio and video media, weblogs, and photographs. He will meet with a group of 10th- and 11th-graders monthly to engage the students in the research happening in the lab and at the telescope in Chile. The presentation materials developed for this program will then be expanded to reach a broader audience through existing programs such as the annual physics fair at Johns Hopkins, as well as through an interactive presentation on the World Wide Telescope web site. This narrative tour of the sky as seen by project telescopes will present the project's results in cosmology to a broad, global audience.