Collaborative Research: Imaging the Beginning of Time from the South Pole: Completing the BICEP Array Survey

合作研究：从南极想象时间的开始：完成 BICEP 阵列调查

• 批准号: 2220448
• 负责人: Chao-Lin Kuo
• 金额: $ 160.87万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2027-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2220448&HistoricalAwards=false
• 关键词: Collaborative; Research; Imaging; Beginning; Time

The theory of the "Big Bang" provides an established cosmological model for the origin of our Universe from its earliest known periods through its subsequent large-scale evolution. However, this theory leaves open the question of explaining the initial conditions. Current thoughts are consistent with the entire observable Universe being spawned in a dramatic, exponential "Inflation" of a sub-nuclear volume that lasted about one trillionth of a trillionth of a trillionth of a second. Following this short inflationary period, the Universe continues to expand, but at a less rapid rate. While this basic "Inflationary paradigm" is accepted by most cosmologists, the detailed physics mechanism responsible for inflation is still not known, but there is a testable prediction that this violent space-time expansion would have produced primordial gravitational waves now propagating through the expanding Universe and forming a cosmic gravitational-wave background (CGB). The CGB amplitude defines the energy scale of Inflation that imprints a faint signature in the polarization of the Cosmic Microwave Background (CMB) radiation. Therefore, detecting this polarization signature is arguably the most important goal in cosmology today. This award will continue addressing the oldest question ever posed by mankind "How did the Universe begin?", and it does so via observations made at one of the harshest places on Earth – the Amundsen-Scott South Pole Station in Antarctica. The most recent, community driven Decadal Survey Astro2020 report “Pathways to Discovery in Astronomy and Astrophysics for the 2020s” reaffirmed the importance of search for B-modes polarization signatures of primordial gravitational waves and Inflation, and specifically endorsed the CMB Stage-4 science to be pursued by systematically supported CMB experiments in Antarctica and Chile. The recently released BICEP results place stringent limits on Inflationary models which, for the first time, go well beyond what can be done with temperature data alone, and which rule out two entire classes of previously popular single-field models—natural Inflation and simple monomial potentials. This award aims to complete deployment of all four BICEP Array receivers and then operate them as the Stage-3+ generation observing system. BICEP Array will measure the polarized sky in six frequency bands to reach an ultimate sensitivity to the amplitude of PGW of σ(r) ≲ 0.003, extrapolating from achieved performance, and after conservatively accounting for the Galactic dust, Galactic synchrotron and CMB lensing foregrounds. These measurements will be a definitive test of slow-roll models of Inflation, which generally predict a gravitational-wave signal above approximately r=0.01. BICEP Array will therefore realize the goal set by the NASA/DOE/NSF Task Force for CMB Research in 2005 to achieve sensitivity at this level, and confirmed as “the most exciting quest of all” by the Astro2010, and advance the B-mode search strongly endorsed by the Astro2020 Decadal Survey. The project will continue to provide excellent training for undergraduate and graduate students and postdoctoral fellows including those from underrepresented groups in laboratories that have exceptional track records in this regard. Cosmology and research in Antarctica both capture the public imagination, making this combination a remarkably effective vehicle for stimulating interest in science. This project advances the goals of the NSF Windows on the Universe Big Idea.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.

“大爆炸”理论为我们的宇宙从最早的已知时期到随后的大规模演化的起源提供了一个既定的宇宙学模型，但是，该理论仍然没有解决解释初始条件的问题，目前的想法是一致的。整个可观测的宇宙是在亚核体积的剧烈指数“膨胀”中产生的，这种膨胀持续了大约一万亿分之一秒。在这段短暂的膨胀期之后，宇宙继续膨胀，但以较慢的虽然这种基本的“暴胀范式”被大多数宇宙学家所接受，但造成暴胀的详细物理机制仍然未知，但有一个可检验的预测，即这种剧烈的时空膨胀会产生现在通过宇宙传播的原始引力波。膨胀的宇宙并形成宇宙引力波背景（CGB） CGB 振幅定义了膨胀的能量尺度，在宇宙微波背景的偏振中留下了微弱的特征。因此，探测这种偏振特征可以说是当今宇宙学最重要的目标，该奖项将继续解决人类提出的最古老的问题“宇宙是如何开始的？”，并且它是通过观测来实现的。地球上最恶劣的地方之一——南极洲的阿蒙森-斯科特南极站最新的、社区驱动的十年期调查 Astro2020 报告“天文学和天体物理学的发现之路”。 2020 年代”重申了寻找原初引力波和暴胀的 B 模式偏振特征的重要性，并特别认可了在南极洲和智利进行系统支持的 CMB 实验所追求的 CMB 第四阶段科学。最近发布的 BICEP 结果提出了严格的限制。膨胀模型首次远远超出了单独使用温度数据所能完成的范围，并且排除了以前流行的两类单场该奖项旨在完成所有四个 BICEP 阵列接收器的部署，然后将其作为 Stage-3+ 一代观测系统来测量六个频段的偏振天空。对 PGW 振幅的敏感度为 σ(r) ≲ 0.003，根据已实现的性能推断，并在保守地考虑了银河尘埃、银河同步加速器和 CMB 透镜之后这些测量结果将是对暴胀慢滚模型的明确测试，该模型通常预测 BICEP 阵列将实现大约 r=0.01 以上的引力波信号，从而实现 NASA/DOE/NSF 工作组为 CMB 设定的目标。 2005 年的研究达到了这一水平的灵敏度，并被 Astro2010 确认为“最令人兴奋的探索”，并推进了 Astro2020 强烈支持的 B 模式搜索该项目将继续为本科生、研究生和博士后提供优秀的培训，包括那些在宇宙学和南极洲研究方面拥有杰出记录的实验室的人员，使这一组合成为一个令人惊叹的项目。该项目推进了 NSF 宇宙之窗大创意的目标。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响进行评估，被认为值得支持。审查标准。

项目成果

BICEP/Keck. XVII. Line-of-sight Distortion Analysis: Estimates of Gravitational Lensing, Anisotropic Cosmic Birefringence, Patchy Reionization, and Systematic Errors

二头肌/凯克。

• DOI: 10.3847/1538-4357/acc85c
• 发表时间: 2023-05
• 期刊: The Astrophysical Journal
• 作者: Ade, P. A. R.;Ahmed, Z.;Amiri, M.;Barkats, D.;Thakur, R. Basu;Bischoff, C. A.;Beck, D.;Bock, J. J.;Boenish, H.;Bullock, E.;et al
• 通讯作者: et al

BICEP/Keck. XVI. Characterizing Dust Polarization through Correlations with Neutral Hydrogen

二头肌/凯克。

• DOI: 10.3847/1538-4357/acb64c
• 发表时间: 2023-03
• 期刊: The Astrophysical Journal
• 作者: Ade, P. A. R.;Ahmed, Z.;Amiri, M.;Barkats, D.;Thakur, R. Basu;Bischoff, C. A.;Beck, D.;Bock, J. J.;Boenish, H.;Bullock, E.;et al
• 通讯作者: et al