Quantum Universe

量子宇宙

• 批准号: RGPIN-2020-04316
• 负责人: Turok, Neil
• 金额: $ 2.39万
• 依托单位: University of Waterloo
• 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=763117
• 关键词: Quantum; Universe

The universe arrayed around us provides a marvellous natural physics laboratory. As we look outwards, we see amazing objects like neutron stars and black holes, undergoing extreme physical processes in which the fundamental laws of physics play out in front of our eyes. We see galaxies and stars in the process of forming, developing and aging. We detect the light, radio waves, X--rays, neutrinos and even gravitational waves emitted from each of these, and many other dramatic sources. Seen from our viewpoint outside them, black holes are extremely simple yet paradoxical objects. Reconciling them with quantum physics could lead to revolutionary advances in our understanding of space and time. Observed from our vantage point within it, the universe is likewise remarkably minimal in form, yet equally puzzling. Physics' greatest challenge is to understand this simplicity. To do so we must combine the laws of quantum physics, which are extremely well verified in laboratory experiments, with Einstein's theory of gravity, which accurately describes the structure and evolution of the cosmos. This proposal will support an exceptional cohort of students working to develop Feynman's famous path integral formulation of quantum mechanics with the inclusion of gravity. The proposer pioneered the use of  Picard--Lefschetz theory, an advanced mathematical technique, in combination with ideas such as weak measurement, coming from quantum foundations, and geometrodynamics - the description of quantum spacetime.  These approaches will be combined in a fully quantum description, to understand how classical spacetime emerges from constructive interference and how quantum fluctuations perturb its fabric. One PhD student will work on each of the following objectives. O1: proving the existence of Feynman's path integral for real-time quantum systems, both with and without gravity, and applying this to various systems, O2: modelling the interference patterns produced by coherent sources such as pulsars and fast radio bursts and attempting to reconstruct the source and the lens, O3: studying the quantum behaviour of spacetime including the big bang singularity, the emergence of time and the quantum evaporation of black holes, and O4: developing our recent explanation - the simplest yet proposed - for the cosmological dark matter. The latter rests on imposing a profound symmetry (CPT symmetry) on the vacuum state of the neutrino sector of the standard model of particle physics. Comparison with leading edge observations and predictions for new experiments will be a hallmark of our work.  Our overarching goal is to obtain a consistent quantum understanding of the universe, across all scales, consistent with the known laws of physics as established through experiment and observation. The powerful mathematical tools and techniques we develop are likely to have wide application, for example assisting with the design and data analysis tasks of revolutionary new radio telescopes.

我们周围的宇宙提供了一个奇妙的自然物理实验室。当我们向外看时，我们看到像中子星和黑洞这样令人惊叹的物体，它们正在经历极端的物理过程，在这些过程中，物理学的基本定律在我们眼前发挥作用。我们看到星系和恒星在形成、发展和老化的过程中。我们探测到光，无线电波，X射线，中微子，甚至引力波，从每一个这些发射，和许多其他戏剧性的来源。从我们在黑洞之外的视角来看，黑洞是极其简单但又自相矛盾的物体。将它们与量子物理学结合起来可能会导致我们对空间和时间的理解发生革命性的进展。从我们在其中的Vantage位置观察，宇宙同样是非常微小的形式，但同样令人困惑。物理学最大的挑战是理解这种简单性。要做到这一点，我们必须将量子物理定律与爱因斯坦的引力理论结合起来，量子物理定律在实验室实验中得到了非常好的验证，爱因斯坦的引力理论准确地描述了宇宙的结构和演化。这项提议将支持一群特殊的学生，他们致力于发展费曼著名的量子力学路径积分公式，其中包括引力。该提议者率先使用皮卡德-莱夫谢茨理论，一种先进的数学技术，结合诸如弱测量，来自量子基础和几何动力学-描述量子时空的想法。 这些方法将结合在一个完整的量子描述中，以理解经典时空是如何从相长干涉中出现的，以及量子涨落如何扰动它的结构。一名博士生将致力于以下每个目标。氧气：证明了费曼路径积分在有重力和无重力的实时量子系统中的存在，并将其应用于各种系统，O2：模拟相干源（如射电暴和快速射电暴）产生的干涉图样，并试图重建源和透镜，O3：研究时空的量子行为，包括大爆炸奇点，时间的出现和黑洞的量子蒸发，以及O 4：发展了我们最近提出的宇宙学暗物质的最简单的解释。后者依赖于对粒子物理学标准模型的中微子部分的真空态施加深刻的对称性（CPT对称性）。与前沿观测和新实验预测的比较将是我们工作的一个标志。 我们的首要目标是在所有尺度上获得对宇宙的一致量子理解，与通过实验和观察建立的已知物理定律一致。我们开发的强大的数学工具和技术可能会有广泛的应用，例如协助革命性的新射电望远镜的设计和数据分析任务。