Cosmology in the Non-Linear Regime with Weak Gravitational Lensing

刘佳被授予美国国家科学基金会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项目。刘将开发理论模型，并用它们来解释观测结果，这些观测结果可能为暗能量提供新的见解，以及一种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限制，拟议的研究将显著提高我们对宇宙的理解。在她工作的教育部分，刘将担任普林斯顿监狱教学倡议(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对科学的兴趣，并获得成功狱外生活的技能和资格。刘将进行N体射线跟踪模拟，以调查非高斯统计数据，这些统计数据对于正确解释星系的弱透镜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条件改进近两倍，从而使先进的阿塔卡马宇宙学望远镜和Hyper SuPrime-Cam的测量观测产量翻一番；以及(2)揭示中微子质量等级，这是粒子物理学中的一个长期问题。这也将促进我们对弱透镜系统学的理解，包括光度学红移、星系的内在排列和形状测量。减少来自这些系统学的噪音将进一步改善宇宙学的约束。作为PTI的一名志愿者讲师，刘将向囚犯教授大学水平的数学和科学课程，设计一门新的预科物理和天文学课程，并培训其他讲师来教授新设计的课程。

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.