Exploring the Universe with radio and optical galaxy surveys

该项目将提供最大的宇宙三维地图，覆盖120亿年的宇宙历史。它将利用射电强度测绘和光学星系测量来提供至少比目前最先进的水平好10倍的测量结果。创新的观测、计算和统计方法将被用来回答天体物理学中最重要的两个问题：暗能量的本质是什么，以及星系是如何演化的。为了回答这些问题，英国主要参与的光学星系调查将被用作本十年精密宇宙学的主要资源。即将到来的最先进的宇宙学实验，如欧空局的欧几里德卫星任务，将扫描大量数据，并回答关于宇宙的开始、演化和后期加速膨胀的基本问题。与此同时，对红移的中性氢21厘米线的射电观测，以及SKA天文台(SKAO)及其猫鼬前身等新仪器，将为探索和理解宇宙提供一种新的方式。该项目有两个首要目标：第一个目标是利用像Meerkat和Skao这样的射电望远镜开启精密宇宙学时代。我正在领导一项探测目标信号的创新技术的开发，称为“中性氢强度测绘”。这项技术可以彻底改变我们对星系演化和宇宙学的理解，但目前它受到系统效应和缺乏现实模拟的严重限制。该项目将提供所需的新的模拟和分析方法，以建立作为宇宙学关键资源的强度图。第二个目标是解决光学星系探测中最大的理论挑战，例如欧空局的欧几里德任务。这些调查提供的大部分高精度数据都是在小规模范围内进行的，建模难度极大。如果没有重大进展，全球误差预算将受到我们理论理解的限制，而不是统计或系统误差。该项目将确保模型赶上数据敏感度，并利用机器学习技术开发新的分析技术。这笔赠款将巩固由阿尔基蒂斯·波尔西杜发起的UKRI FLF研究小组的世界领先地位。

This project will provide the largest 3-dimensional map of the Universe, covering 12 billion years of cosmic history. It will exploit radio intensity mapping and optical galaxy surveys to deliver measurements that are at least 10 times better than the current state-of-the-art. Innovative observational, computational, and statistical methods will be used to answer two of the most important questions in astrophysics: what is the nature of dark energy, and how galaxies evolve. To answer these questions, optical galaxy surveys with major UK involvement are going to be used as the main resource for precision cosmology in this decade. Forthcoming state-of-the-art cosmological experiments like ESA's Euclid satellite mission will scan huge volumes and answer fundamental questions about the Universe's beginning, evolution, and late time accelerated expansion. At the same time, radio observations of the redshifted neutral hydrogen 21cm line and new instruments like the SKA Observatory (SKAO) and its MeerKAT precursor, will provide a novel way to explore and understand the Universe.The project has two overarching aims: the first aim is to kick-off the era of precision cosmology using radio telescopes like MeerKAT and the SKAO. I am leading the development of an innovative technique to detect the target signal, called "neutral hydrogen intensity mapping". This technique can revolutionise our understanding of galaxy evolution and cosmology, but it is currently severely limited by systematic effects and lack of realistic simulations. The project will deliver the new simulations and analysis methods needed in order to establish intensity mapping as a key resource for cosmology. The second aim is to address the biggest theoretical challenge in optical galaxy surveys such as ESA's Euclid mission. Most of the high precision data these surveys deliver are within the small-scale regime, which is extremely challenging to model. Without significant progress, the global error budget will be limited by our theoretical understanding rather than statistical or systematic errors. The project will ensure the models catch up with the data sensitivity and develop new analysis techniques using machine learning technologies. This grant will consolidate the world-leading position of the UKRI FLF research group initiated by Alkistis Pourtsidou.