NSF-BSF: Dark-Matter Interactions at Cosmic Dawn

在暗物质被发现几十年后，它仍然是天体物理学中存在时间最长的谜题之一。这个项目将利用宇宙黎明时期的观测结果，也就是第一个星系形成的时候，来推进我们对暗物质的理解。德克萨斯大学和以色列本古里安大学的科学家将开发一个理论框架来模拟不同暗物质场景下21厘米的氢信号，并使用它来分析来自氢时代再电离阵列（HERA）的数据。即使在明确探测到21厘米信号之前，这一提议也将为宇宙黎明期间暗物质与我们扇区之间的相互作用提供新的见解。它也将进一步我们的研究速度引起的声波振荡（VAOs），以及它们作为一种独特的探测暗物质的有用性。作为该项目的一部分，该团队将为几名研究生和博士后提供指导。此外，为了促进西班牙裔和拉丁裔学生参与科学研究，该团队将发起并领导一个以天体物理学和宇宙学为重点的西班牙语期刊俱乐部。该项目由美国国家科学基金会和美以两国国家科学基金会共同支持，旨在进一步促进两国天体物理学界的合作，暗物质（DM）本质的宇宙学限制主要来自宇宙微波背景（CMB，从z~1000）或宇宙晚期（z~0）的数据。相比之下，我们对z~5-25宇宙黎明中期的暗物质知之甚少。宇宙黎明看到了第一个结构的形成，也是宇宙历史上气体最冷的时候。因此，它是寻找可能加热气体的新过程的理想场所，例如DM的衰变或湮灭；pi将使用21厘米的波动，其中前景被限制为一个“楔子”，以对DM施加新的限制，这对系统和前景都是强大的。这包括使用HERA数据和将要开发的公共代码来彻底测试所建议的模型，以解释从检测全球EoR特征（EDGES）实验中声称的21厘米检测。该项目还将开发和实施新的工具，以搜索数据中其他现象学上有趣的模型，包括它们如何影响宇宙黎明时VAOs的振幅和形状。公共软件套件是该项目的重要交付成果，因为它将与公共玻尔兹曼解算器接口，允许与CMB和大型结构联合分析21厘米数据。该奖项反映了美国国家科学基金会的法定使命，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。

Decades after its discovery, dark matter remains one of the longest-standing puzzles in astrophysics. This project will use observations from the cosmic-dawn epoch, when the first galaxies formed, to advance our understanding of dark matter. Scientists at the University of Texas and Ben Gurion University in Israel will develop a theoretical framework to model the 21-cm signal of hydrogen in the presence of different dark-matter scenarios, and use it to analyze data from the Hydrogen Epoch of Reionization Array (HERA). Even before a clear detection of the 21-cm signal is reached, this proposal will deliver new insights on the interactions between dark matter and our sector during cosmic dawn. It will also further our study of velocity-induced acoustic oscillations (VAOs), and their usefulness as a unique probe of the dark sector. As part of this project, the team will provide mentoring for several graduate students and postdocs. In addition, in an effort to promote inclusion of Hispanic and Latinx students in scientific research, the team will initiate and lead a Spanish-language journal club focused on astrophysics and cosmology. This project is supported by both the National Science Foundation and the US-Israel Binational Science Foundation to further collaborations between the astrophysical communities in the two countries, Cosmological constraints on the nature of dark matter (DM) are dominated by data from either the cosmic microwave background (CMB, from z~1000) or the late Universe (z~0). By comparison, little is known about dark matter from the intermediate epoch of cosmic dawn at z~5-25. Cosmic dawn saw the first structure formation and was the time when the gas was coldest in cosmic history. As such, it is an ideal place to look for new processes that may heat up the gas, such as decaying or annihilating DM; or cool it down, such as electrically charged DM. The PIs will use 21-cm fluctuations, where foregrounds are limited to a “wedge”, to place new limits on DM that are robust to systematics and foregrounds. This includes using HERA data and the public code to be developed to thoroughly test the models suggested to explain the claimed 21-cm detection from the Experiment to Detect the Global EoR Signature (EDGES). This project will additionally develop and implement novel tools to search for other phenomenologically interesting models in data, including how they affect the amplitude and shape of VAOs at cosmic dawn. The public software suite is an important deliverable of this project, as it will interface with public Boltzmann solvers, allowing for joint analyses of 21-cm data with the CMB and large-scale structure.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.