Clocks and singularities in quantum gravity and quantum cosmology

经典广义相对论的方程可以写在任意坐标系中，特别是使用不同的时间标准(不同的“时钟”)，这可以被视为与不同的观察者有关。然而，量子理论对时钟的选择很敏感，不同的时钟会导致物理行为不同的不等价理论。在这个项目中，我们将研究在量子引力和量子宇宙学中使用不同时钟的含义，特别是关于引力奇点的可能分辨率。我们将研究宇宙学系统以及黑洞。

The equations of classical general relativity can bewritten in arbitrary coordinate systems, in particular using differentstandards of time (different "clocks") which can be seen as relating todifferent observers. Quantum theory, however, is sensitive to the choiceof clock and different clocks can lead to inequivalent theories withdifferent physical behaviour. In this project we will study theimplications of using different clocks in quantum gravity and quantumcosmology, in particular regarding the possible resolution ofgravitational singularities. We will study cosmological systems as wellas black holes.