Discrete to continuum transition in quantum gravity models

对空间和时间本质的更深入理解过去是，现在仍然是物理学从一开始就发展的主要驱动因素之一。它最终形成了爱因斯坦的广义相对论，指出时空是一个动态的物体，与宇宙中的所有物质相互作用，产生引力。但除此之外，我们知道物质是由量子理论描述的，因此时空也必须是量子的。构建时空量子理论，进而构建引力理论，是当今基础物理学面临的最大挑战之一。 因此，在广义相对论的量子理论中，我们期望时空是从某些基本量子结构或成分中动态涌现出来的。许多量子引力方法的主要问题是展示一个光滑的时空，以及引力的动力学编码，是如何从通常离散的基本构建块中出现的。 该提案的目的是使人们对这一问题有一个新的和更深刻的理解。 为此，我们将使用最近为凝聚态系统开发的强大工具和技术。在那里，人们追求类似的问题，即从原子组成推断材料的宏观性质。 更好地理解这些时空问题将深刻影响我们对基础物理学的理解，并肯定会带来令人惊讶的见解。

A deeper understanding of the nature of space and time was and still is one of the main driving factors for the development of physics from its very beginnings. It culminated in Einstein's theory of general relativity, stating that space-time is a dynamical object, interacting with all the matter of the universe and giving rise to the gravitational force. But in addition, we know that matter is described by quantum theory, and therefore space-time must also be quantum. The construction of a quantum theory of space-time, and by extension gravity, is one of the biggest challenges for fundamental physics today. In a quantum theory of general relativity, we therefore expect space-time to be dynamically emergent from some fundamental quantum structures or constituents. The main problem of many quantum gravity approaches is to show how a smooth space-time, encoding moreover the dynamics of gravity, emerges from the often discrete fundamental building blocks. The aim of the proposal is to bring a new and deeper understanding to this question. To this end we will use powerful tools and techniques which were recently developed for condensed matter systems. There, similar questions are pursued, namely to deduce the macroscopic properties of a material from its atomic constituents. A better understanding of these questions for space-time will impact our understanding of fundamental physics deeply and will certainly lead to surprising insights.