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

物质在整个宇宙中的分布携带着关于宇宙的起源、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：大部分物质以不可见暗物质的形式存在，因此无法直接观察。相反，必须使用引力透镜等技术来推断物质的位置。引力透镜是光在重力作用下发生的弯曲。有了这项研究计划，夏威夷大学和芝加哥大学的科学家们将从最先进的天文测量中分析四种不同的、高度互补的物质分布探测器，以获得对宇宙性质的精确和公正的限制。该团队将使用暗能量调查(DES)对星系位置和引力透镜的测量，南极望远镜(SPT)和阿塔卡马宇宙学望远镜(ACT)对来自宇宙微波背景(CMB)的光的引力透镜的测量，以及来自SPT和ACT的CMB光与电子散射的测量。通过协调分析这些互补的探测器，该团队将减少宇宙性质的不确定性，最大限度地减少约束中的潜在偏差，并获得更完整的物质分布图景。该奖项还将支持开发新的教学模块，旨在让高中生和本科生有机会从真实数据中学习并获得数据科学方面的实践经验。物质分布的统计数据是由宇宙常数和冷暗物质(LCDM)模型预测的，将这些预测与观测结果进行比较是当前和未来宇宙测量的关键目标。最近，银河系调查对晚时间物质分布的测量显示，与假设LCDM的早期宇宙测量结果不一致的迹象。这种不一致的原因可能是LCDM的根本问题，或者是影响测量的系统不确定性。使用来自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效应之间的交叉相关性，以便执行与LCDM的紧张关系的最终评估，测试替代宇宙学模型，并在未来的调查中实现改进的约束。该提案的更广泛影响将是为高中、本科生和研究生提供数据科学方面的培训，并增加公众对天文测量的参与。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数据中学习。这些教学工具将在火奴鲁鲁和芝加哥的课堂上实施。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.