Cosmological tests of fundamental physics

基础物理的宇宙学测试

• 批准号: RGPIN-2020-04977
• 负责人: Pogosian, Levon
• 金额: $ 2.99万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762552
• 关键词: Cosmological; tests; fundamental; physics

We live in a golden age of cosmology. The next generation of optical and radio telescopes will complete the detailed 3D map of the structure in the universe, revealing its evolution through multiple epochs. Upcoming cosmic microwave background (CMB) experiments will produce high quality polarization maps potentially confirming the quantum origin of the initial inhomogeneities that seeded formation of stars and galaxies. Canadian astronomers are actively involved in these efforts. My proposal is inspired by the opportunities presented by the upcoming experiments for resolving some of the long-standing puzzles in particle physics and cosmology, such as the nature of dark matter and dark energy. My group is in a good position to solidify its leading role in designing and applying new tests of fundamental physics, while working in close partnership with observational teams. The research program I propose is broadly grouped into two main themes: One focuses on the dynamics of the late time universe and includes studies of dark energy, cosmological test of general relativity and alternative theories of gravity. The other will concern the early universe and using cosmology as a laboratory for testing particle physics. With dark matter and dark energy making up 95% of the energy content of the universe, and with general relativity only weakly tested over cosmological times and distances, there is a considerable interest in developing and testing alternative theories of gravity. My group will develop theoretical frameworks and numerical tools that, in addition to testing specific theories of dark energy and modified gravity, will answer a set of important qualitative questions in as model-independent way as possible. Such questions would include whether dark energy density remains constant in time, whether the equivalence principle holds on cosmological scales and if there are interactions between the dark components. Our work will build on existing long term collaborations with team members of upcoming surveys such as DESI, Euclid and LSST. The expanding universe acts as a microscope revealing physics at energies beyond the reach of particle accelerators. CMB has been our key source of information that will eventually be complemented by gravitational wave (GW) observations from future experiments such as LISA. This proposal includes studying the phase transitions that took place in the early universe, along with their relics, such as primordial magnetic fields and cosmic strings, and their characteristic CMB and GW signatures. I will also study axion strings and their decay into dark matter. My work in this area will form part of my contribution to the CMB-S4 collaboration. The SFU Cosmology Group, with its combined expertise in theory, statistics, computing and data analysis, provides a stimulating environment for developing and testing new ideas, and unique opportunities for training HQP in areas of active international interest.

我们生活在宇宙学的黄金时代。下一代光学和射电望远镜将完成宇宙结构的详细 3D 地图，揭示其多个时代的演化。即将进行的宇宙微波背景（CMB）实验将产生高质量的偏振图，有可能证实恒星和星系形成的初始不均匀性的量子起源。加拿大天文学家积极参与这些努力。 我的提议受到即将进行的实验所提供的机会的启发，这些实验旨在解决粒子物理学和宇宙学中一些长期存在的难题，例如暗物质和暗能量的本质。我的团队处于有利位置，可以巩固其在设计和应用基础物理新测试方面的主导作用，同时与观测团队密切合作。我提出的研究计划大致分为两个主题：一是关注晚期宇宙的动力学，包括暗能量、广义相对论的宇宙学测试和引力的替代理论的研究。另一个将涉及早期宇宙并使用宇宙学作为测试粒子物理的实验室。由于暗物质和暗能量占宇宙能量的 95%，并且广义相对论在宇宙时间和距离上的测试仅很弱，因此人们对开发和测试替代引力理论有着相当大的兴趣。我的小组将开发理论框架和数值工具，除了测试暗能量和修正引力的具体理论之外，还将以尽可能独立于模型的方式回答一系列重要的定性问题。这些问题包括暗能量密度是否随时间保持恒定、等效原理在宇宙学尺度上是否成立以及暗成分之间是否存在相互作用。我们的工作将建立在与即将进行的 DESI、Euclid 和 LSST 等调查的团队成员现有的长期合作基础上。膨胀的宇宙就像一台显微镜，揭示了粒子加速器无法达到的能量下的物理现象。 CMB 一直是我们的主要信息来源，最终将通过 LISA 等未来实验的引力波 (GW) 观测得到补充。该提案包括研究早期宇宙中发生的相变及其遗迹，例如原始磁场和宇宙弦，以及它们特有的宇宙微波背景和引力波特征。我还将研究轴子弦及其衰变成暗物质。我在这一领域的工作将构成我对 CMB-S4 合作贡献的一部分。 SFU 宇宙学小组凭借其在理论、统计、计算和数据分析方面的综合专业知识，为开发和测试新想法提供了一个刺激的环境，并为在国际上活跃的领域培训 HQP 提供了独特的机会。