Preparing for and making cosmological measurements from galaxy surveys

过去50年的研究提供了对宇宙的巨大洞察，确定了许多关键参数，如宇宙的年龄和能量密度分量的分裂。令人惊讶的是，这引发了一些大问题：我们不知道宇宙的主要组成部分是什么，也不知道为什么宇宙正在加速膨胀。值得庆幸的是，我们正处于宇宙学实验数据的黄金时代，2019-2024年将是宇宙学极其重要的时期，星系调查将引领令人兴奋的实验进展。拟议的研究方案将准备和利用欧几里德卫星任务的数据，以了解导致宇宙加速膨胀的物理机制，通常称为暗能量。*这项资助的学生将开发和应用使用国际欧几里德卫星任务的数据进行宇宙学测量所需的技术。珀西瓦尔博士在欧几里德联盟中有许多高级科学管理职位，确保工作集中在所需的关键发展上。欧几里德将创建一项宇宙调查，其水平比目前的数据提高了一个数量级。由于计划于2022年启动，最初的工作将集中在为这次任务做准备，然后将重点转移到分析这一应用程序所涵盖的时间表结束时的第一批数据。这项提议的目的是建立一个在加拿大进行这项研究的科学家核心小组，这将继续到欧几里德之后的调查：包括大型天气观测望远镜(LSST)和毛纳凯光谱探测器(MSE)。除了实施和优化基于星系团进行宇宙学测量的已知方法，我们还将考虑更新的技术。使用最近开发的星系围绕空洞的速度模型，该团队将调查我们是否可以进行强有力的基于投影的测量，以测量有空洞的宇宙膨胀。空洞是星系很少的区域，具有一些非常吸引人的特性，使得建模变得简单，例如其中星系的线性运动。最终，我们的目标是找到与基于爱因斯坦宇宙学常数驱动暗能量的和谐模型的偏差。这样的发现将导致我们对宇宙的理解发生根本性的变化。如果我们没有发现这样的偏差，这项研究将提高我们对宇宙学的理解，开发出普遍感兴趣的新统计工具，培训一些学生，并将加拿大置于一个非常令人兴奋的物理学领域的前沿。特别是，学生开发和应用新的统计技术所培养的技能，在学术界内外都将是有用的。

Research over the last 50 years has provided a tremendous insight into the Universe, with many of the key parameters determined such as the age of the Universe and the split of energy-density components. Surprisingly, this has thrown up some big questions: we don't know what the dominant constituents of the Universe are made of, or why the expansion is accelerating. Thankfully, we are in a golden era of experimental data in cosmology, and the period 2019-2024 will be an extremely important one for cosmology with galaxy surveys spearheading exciting experimental advances. The proposed programme of research will prepare for and exploit the data from the Euclid satellite mission to understand the physical mechanism that is causing the accelerated expansion of the Universe, commonly termed Dark Energy.******The students supported by this grant will develop and apply the techniques required to make cosmological measurements using data from the international Euclid satellite mission. Dr Percival has a number of senior scientific management positions in the Euclid Consortium ensuring that the work concentrates on the critical developments that are required. Euclid will create a survey of the Universe at a level that is an order of magnitude improvement over current data. As it is scheduled to launch in 2022, the initial work will concentrate on preparing for this mission, before focus shifts to analysing the first data towards the end of the timeline covered by this application. The intention with this proposal is to set up a core group of scientists undertaking this research within Canada, which will continue to the generation of surveys to come after Euclid: including the Large Synoptic Survey Telescope (LSST) and the Maunakea Spectroscopic Explorer (MSE).******Alongside implementing and optimising known methods for making cosmological measurements based on the clustering of galaxies, we will consider more novel techniques. Using a recently developed model for the velocities of galaxies around voids, the team will investigate whether we can make robust projection-based measurements to measure cosmological expansion with voids. Voids are regions with very few galaxies, and have some very attractive properties that make modelling simple, such as the linear motions of galaxies within them.******Ultimately, our ambition is to find a deviation from the concordance model based on Einstein's cosmology constant driving Dark Energy. Such a discovery would lead to a fundamental change in our understanding of the Universe. In the event that we do not find such a deviation, the research will have improved our understanding of cosmology, developed new statistic tools of universal interest, trained a number of students, and placed Canada at the forefront of a very exciting field in physics. In particular, the skills developed by the students developing and applying novel statistical techniques, will be useful both within and outside of academia.