Dynamics in modified theories of gravity

修正引力理论中的动力学

• 批准号: 2614536
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2614536
• 关键词: Dynamics; modified; theories; gravity

Although the problem of time in quantum gravity is often dismissed as "metaphysical" by phenomenologists, it is hard to see how quantum gravity could ever make contact with the real world without this crucial ingredient. In this project we explore the observational implications of the possibility that the duals of the constants of nature are precisely the much sought-after definitions of time - or times - in quantum gravity. Preliminary work shows that not only a sound semi-classical limit is obtained, but also that quantum cosmology could then have direct observational implications "here and now" (on a cosmological scale). The fact that the universe has recently changed gears, from decelerated to accelerated expansion, could signal a quantum reflection or bounce in connection space, as well as the handover of one time to another (duals, for example, to Newton's and the cosmological ``constants''). Collaborative work leading to a number of papers exploring this possibility in detail could bring quantum cosmology out of the realm of speculation and the unattainable Planck epoch, rendering the whole field finally testable. Ironically the most philosophical of all the problems - that of time - might be the missing clue.

尽管量子引力中的时间问题经常被现象学家斥为“形而上学”的问题，但如果没有这个关键因素，很难想象量子引力如何与真实的世界联系起来。在这个项目中，我们将探索自然常数的绝对值恰好是量子引力中广受欢迎的时间（或时间）定义的可能性的观测意义。初步的工作表明，不仅获得了一个健全的半经典极限，而且量子宇宙学可以在“此时此地”（在宇宙学尺度上）有直接的观测意义。事实上，宇宙最近已经改变了齿轮，从减速到加速膨胀，可能标志着连接空间中的量子反射或反弹，以及一个时间到另一个时间的移交（例如，牛顿和宇宙学的“常数”）。合作工作导致了许多论文详细探索这种可能性，可以将量子宇宙学带出猜测的领域和无法实现的普朗克时代，使整个领域最终可以测试。具有讽刺意味的是，所有问题中最具哲学意义的问题--时间问题--可能就是那条缺失的线索。