Collaborative Research: Combining Galaxy and Cosmic Microwave Background Surveys for Precise and Robust Constraints on Cosmology

宇宙中物质的分布携带着关于宇宙起源、未来和组成的信息。然而，获得物质分布的高精度测量是具有挑战性的：大多数物质是以不可见的暗物质的形式存在的，因此不可能直接观察。相反，必须使用引力透镜（引力使光弯曲）等技术来推断物质的位置。 通过这项研究计划，夏威夷大学和芝加哥大学的科学家将分析来自最先进的天文调查的物质分布的四种不同且高度互补的探测器，以获得对宇宙属性的精确和无偏约束。该团队将使用暗能量调查（DES）的星系位置和星系引力透镜的测量，南极望远镜（SPT）和阿塔卡马宇宙学望远镜（ACT）的宇宙微波背景（CMB）光的引力透镜的测量，最后，来自SPT和ACT的CMB光与电子散射的测量。通过分析这些互补的探测器，研究小组将减少宇宙性质的不确定性，最大限度地减少其约束的潜在偏差，并获得更完整的物质分布图。该奖项还将支持开发新的教学模块，旨在让高中和本科生有机会从真实的数据中学习，并获得数据科学的实践经验。 宇宙学常数和冷暗物质（LCDM）模型预测了物质分布的统计数据，将这些预测与观测结果进行比较是当前和未来宇宙调查的关键目标。最近，从星系巡天中对晚期物质分布的测量显示出与假设LCDM的早期宇宙测量结果的外推不一致的迹象。这种不一致可能是由于LCDM的基本问题，或者是由于影响测量的系统不确定性。利用来自DES、SPT和ACT的新数据，该团队将测量和分析CMB透镜、星系位置、星系透镜和热Sunyaev Zel'dovich效应之间的互相关性，以便对LCDM的张力进行明确的评估，测试替代宇宙学模型，并在未来的调查中改进约束条件。 该提案的更广泛影响将是为高中、本科和研究生提供数据科学培训，并增加公众对天文调查的参与。PI将开发一套基于Python笔记本的新教学工具，让高中生和本科生有机会从真实的数据中学习。这些教学工具将在檀香山和芝加哥的教室中实施。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The distribution of matter throughout the cosmos carries information about the origin, future, and composition of the Universe. However, obtaining high-precision measurements of the matter distribution is challenging: most of the matter is in the form of invisible dark matter, making it impossible to observe directly. Instead, techniques such as gravitational lensing – the bending of light by gravity – must be used to infer where the matter is. With this research program, scientists at the University of Hawaii and the University of Chicago will analyze four different and highly complementary probes of the matter distribution from state-of-the-art astronomical surveys to obtain precise and unbiased constraints on the properties of the Universe. The team will use measurements of galaxy positions and gravitational lensing of galaxies from the Dark Energy Survey (DES), measurements of gravitational lensing of light from the cosmic microwave background (CMB) by the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT), and finally, measurements from SPT and ACT of the scattering of CMB light with electrons. By analyzing these complementary probes in concert, the team will reduce uncertainties on the properties of the Universe, minimize potential biases in their constraints, and obtain a more complete picture of the matter distribution. This award will additionally support development of new teaching modules designed to give high school and undergraduate students the opportunity to learn from real data and gain hands-on experience in data science. Statistics of the matter distribution are predicted by the cosmological constant and cold dark matter (LCDM) model, and comparing these predictions to observations is a key goal of current and future cosmic surveys. Recently, measurements of the late-time matter distribution from galaxy surveys have shown hints of disagreement with extrapolations of early-Universe measurements that assume LCDM. This disagreement could result from fundamental problems with LCDM, or from systematic uncertainties impacting the measurements. Using new data from DES, SPT, and ACT, the team will measure and analyze cross-correlations between CMB lensing, galaxy positions, galaxy lensing, and the thermal Sunyaev Zel'dovich effect in order to perform a definitive assessment of tension with LCDM, test alternative cosmological models, and enable improved constraints with future surveys. The broader impacts of the proposal will be to provide training in data science to high school, undergraduate and graduate students, and to increase public engagement with astronomical surveys. The PIs will develop a set of new teaching tools based on Python notebooks that give high school and undergraduate students the opportunity to learn from real data. These teaching tools will be implemented in classrooms in Honolulu and Chicago.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.