Cosmology in the Non-Linear Regime with Weak Gravitational Lensing

Jia Liu被授予NSF天文学和天体物理学博士后奖学金，在普林斯顿大学开展研究和教育计划。Liu将开发理论模型，并利用它们来解释观测结果，这些观测结果可以为暗能量提供新的见解，以及测量中微子总质量的方法。“暗能量”是一种未知形式的能量，它加速了宇宙的膨胀。通过改善对关键宇宙学参数的约束，拟议中的研究将大大提高我们对宇宙的理解。对于她工作的教育部分，刘将担任普林斯顿监狱教学计划（PTI）的志愿者讲师，在那里她将教授大学水平的数学和科学课程，包括一门新的预科物理和天文学课程，旨在帮助囚犯发现他们的兴趣科学并获得在监狱外生活取得成功的技能和资格。 Liu将进行N体射线追踪模拟，以研究非高斯统计数据，这些数据对于正确解释星系的弱透镜效应和宇宙微波背景至关重要。拟议的工作有可能（1）将暗能量状态方程的约束提高近两倍，从而使高级阿塔卡马宇宙学望远镜和Hyper Suprime-Cam的调查观测结果增加一倍;（2）揭示中微子质量层次，这是粒子物理学中的一个长期问题。它也将推进我们对弱透镜系统学的理解，包括光度红移，星系的内在排列和形状测量。减少这些系统学的噪音将进一步改善宇宙学的约束。作为PTI的志愿者教师，刘将为囚犯教授大学水平的数学和科学课程，设计一个新的预备物理学和天文学课程，并培训其他教师教授新设计的课程。

Jia Liu is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Princeton University. Liu will develop theoretical models and use them to interpret observations that could provide new insight into dark energy, as well as a way to measure the total mass of neutrinos. "Dark energy" is the term for the unknown form of energy that is accelerating the expansion of the Universe. By improving constraints on key cosmological parameters, the proposed research would significantly improve our understanding of the Universe. For the education component of her work, Liu will serve as a volunteer instructor for Princeton's Prison Teaching Initiative (PTI), where she will teach college level mathematics and science courses, including a new preparatory physics and astronomy course aimed at helping inmates discover their interest in science and acquire the skills and credentials to succeed in life outside prison. Liu will undertake N-body ray-tracing simulations to investigate non-Gaussian statistics that are essential for a proper interpretation of the weak lensing of galaxies and the cosmic microwave background. The proposed work has the potential to (1) improve constraints on the dark energy equation of state nearly twofold, thereby doubling the output of survey observations with Advanced Atacama Cosmology Telescope and the Hyper Suprime-Cam; and (2) shed light on the neutrino mass hierarchy, a long-standing problem in particle physics. It will also advance our understanding of weak lensing systematics, including photometric redshift, intrinsic alignment of galaxies, and shape measurements. Reducing noise from these systematics will further improve cosmological constraints. As a volunteer instructor at PTI, Liu will teach college level mathematics and science courses to inmates, design a new preparatory physics and astronomy course, and train other instructors to teach the newly designed course.