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力，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成分是由什么组成的，或者为什么膨胀正在加速。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年将是宇宙学的一个极其重要的时期，星系调查将引领令人兴奋的实验进展。拟议的研究方案将为欧几里得卫星使命的数据做准备并加以利用，以了解造成宇宙加速膨胀的物理机制，即通常所说的暗能量。由该补助金资助的学生将开发和应用所需的技术，利用国际欧几里得卫星使命的数据进行宇宙学测量。Percival博士在欧几里得联盟中担任了许多高级科学管理职位，以确保工作集中在所需的关键发展上。欧几里得将创造一个宇宙的调查水平，是一个数量级的改善，比目前的数据。由于它计划于2022年发射，最初的工作将集中在为这一使命做准备，然后重点转移到分析该应用程序所涵盖的时间轴结束时的第一批数据。这项建议的目的是在加拿大建立一个从事这项研究的科学家核心小组，该小组将继续进行欧几里得之后的巡天工作：包括大型综合巡天望远镜和毛纳基光谱探测器。除了实施和优化已知的方法，使宇宙学测量的基础上集群的星系，我们将考虑更多的新技术。使用最近开发的空洞周围星系速度模型，研究小组将研究我们是否可以进行强大的基于投影的测量来测量空洞的宇宙膨胀。空洞是一个星系很少的区域，并且具有一些非常吸引人的特性，使建模变得简单，例如星系在其中的线性运动。最终，我们的目标是找到一个偏离基于爱因斯坦宇宙学常数驱动暗能量的和谐模型。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，开发新的普遍感兴趣的统计工具，培训一些学生，并将加拿大置于物理学中一个非常令人兴奋的领域的最前沿。特别是，学生开发和应用新的统计技术所开发的技能，将在学术界内外都是有用的。

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.