Measuring Dark Energy Properties with 3D Weak Lensing

为了解决宇宙学中最重要的问题，需要最好和最全面的数据分析方法。引力透镜效应被广泛接受为这样一种方法，即由于存在巨大的物体使时空局部扭曲，光子从直线路径偏转。这一由爱因斯坦预言的现象导致了广义相对论在1919年被接受为我们的权威引力理论。现在，在这一发现近100年后，同样的现象被应用于宇宙大尺度结构的光透镜，作为距离或回顾时间的函数，使我们能够绘制出宇宙的三维暗物质结构及其膨胀历史。这种透镜信息和距离的组合被称为3D弱透镜。这个博士项目将建立在这个基础上，并将最好的分析方法应用于最好的数据。需要发展三维弱透镜有几个原因：1)需要包括新的理论模型，特别是需要包括广义相对论修正的参数化，以包括解释暗能量的潜在机制；2)需要包括系统效应，特别是那些由星系排列引起的，可以模拟弱透镜信号的效应。没有这些改进，3D弱透镜就无法发挥其全部潜力。这个博士学位将把这些最新的发展应用到最先进的引力透镜数据集上：154平方度的CFHTLenS调查已经可用，1500平方度的ESO KiDS调查现在正在观测数据。此外，将研究三维弱透镜- cmb相互关联统计数据，目的是将其应用于KiDS和普朗克。最后，该项目将构建预计用于即将到来的欧几里得任务的分析工具，其中MSSL将发挥主导作用。为了确保成功获得博士学位，该项目包含理论，模拟和数据分析元素，这些元素是灵活的，可以适应学生的技能和专业知识。

To address the most important questions in cosmology requires the best and most comprehensive data analysis methods. Gravitational lensing, the effect whereby photons are deflected from a straight-line path by the presence of a massive object distorting spacetime locally, is widely accepted to be such a method. This phenomenon, predicted by Einstein, led to the acceptance of General Relativity as our canonical theory gravity in 1919. Now, almost 100 years after this discovery this same phenomenon applied to the lensing of light by large-scale structures of the Universe, as a function of distance or look-back time, enables us to map the 3D dark matter structure of the Universe as well as its expansion history. This combination of lensing information and distance is known as 3D weak lensing this PhD project will build on this foundation, and apply the best analysis methods to the best data available.Development of 3D weak lensing is required for several reasons 1) new theoretical models need to be included, in particular parameterizations of modifications of gravity that extend General relativity to include a potential mechanism to explain dark energy 2) systematic effects, in particular those caused by the alignment of galaxies, that can mimic the weak lensing signal, need to be included. Without these improvements 3D weak lensing cannot reach its full potential.This PhD will apply these new developments the state-of-the-art gravitational lensing data sets: the 154 square degree CFHTLenS survey which is already available and the 1500 square degree ESO KiDS survey that is observing data now. In addition 3D weak lensing-CMB cross correlation statistics will be investigated with an aim to apply this to KiDS and Planck. Finally, this project will build the analysis tools expected to be used in the upcoming ESA Euclid mission in which MSSL has a leading role. In order to ensure a successful PhD this project contains theoretical, simulation and data analysis elements that are flexible such that they can fit with the students skills and expertise.