Unveiling the growth of structure in the Dark Universe

揭示黑暗宇宙中结构的生长

• 批准号: EP/Y03015X/1
• 负责人: Benjamin Joachimi
• 金额: $ 245.42万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FY03015X%2F1
• 关键词: Unveiling; growth; structure; Dark; Universe

The accelerated expansion of the Universe in recent cosmic times is one of the most important unexplained observations in modern physics. It has profound implications in that the cosmos could be permeated by a new, exotic matter component known as dark energy, or that one of the most successful theories of physics, Einstein's general relativity, breaks down on cosmological scales.Emerging tensions between measurements in the late and early Universe are tantalising signs of a potential paradigm change away from the current cosmological standard model. The most promising route to shedding light on this key open problem is to explore the cosmic large-scale structure with multiple probes extracted from large galaxy surveys. I will map the growth of fluctuations in the matter distribution over an unprecedentedly wide range of cosmic history at per-cent level precision, enabling decisive conclusions on cosmic tensions and broad classes of alternative cosmological models. To this end, I will exploit two of the leading galaxy surveys of the decade, which are about to start delivering data: the ESA Euclid space mission and the DESI project, the largest spectroscopic galaxy survey ever undertaken. I will employ combined measurements of the clustering of galaxies, the gravitational lensing effect ongalaxies, as well as the spatial distribution of quasars and of imprints of large-scale structure in their spectra. The joint analysis in overlapping cosmic volumes ensures a maximum of robust constraints on cosmology and on the astrophysical processes that link galaxies to the underlying dark matter distribution. The fidelity of results is advanced through dedicated calibration measurements pushed far beyond the state of the art, and by abandoning the conventional data analysis in favour of a novel forward-modelling approach via fast, highly multiplexed simulations and machine learning-assisted inference techniques.

宇宙在近代的加速膨胀是现代物理学中最重要的无法解释的观测之一。它具有深远的意义，因为宇宙中可能充满了一种新的、奇异的物质成分，即暗能量，或者最成功的物理学理论之一爱因斯坦的广义相对论在宇宙学尺度上崩溃了。晚期和早期宇宙测量之间出现的紧张关系是当前宇宙学标准模型可能发生范式变化的诱人迹象。揭示这个关键的开放问题的最有希望的途径是用从大型星系调查中提取的多个探测器来探索宇宙的大尺度结构。我将以百分之一的精确度绘制宇宙历史上前所未有的广泛范围内物质分布波动的增长，从而对宇宙张力和广泛的替代宇宙学模型得出决定性的结论。为此，我将利用十年来两个主要的星系调查，它们即将开始提供数据：欧空局的欧几里得空间使命和DESI项目，这是有史以来最大的光谱星系调查。我将使用星系团的组合测量，星系的引力透镜效应，以及类星体的空间分布和它们光谱中大尺度结构的印记。对重叠宇宙体积的联合分析确保了对宇宙学和将星系与潜在暗物质分布联系起来的天体物理过程的最大限度的鲁棒约束。通过远超现有技术水平的专用校准测量，以及通过放弃传统的数据分析，支持通过快速，高度复用的模拟和机器学习辅助推理技术的新型前向建模方法，提高了结果的保真度。