ʻWhat is the nature of space and time?ʼ This is a question that has accompanied the development of physics through the centuries. It culminated in Einsteinʼs 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, 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, with the potential to completely change our understanding of space and time.
In such a quantum theory, we therefore expect space-time to be dynamically emergent from some fundamental structures or constituents. Different approaches are typically of a dissimilar foundational composition and sometimes even their principles differ, but all these strategies share the common question of how to obtain, on macroscopic scales, a smooth space-time.
The aim of the workshop is to explore the mechanisms by which quantum space-times appear within the assembled frameworks and to understand the properties of these resultant quantum space-times. Thus, it will include a review of the various approaches, their fundamental principles, as well as the topics, techniques and problems shared by most of them. These include the task of obtaining the semi-classical or large-scale limit from a fundamental, microscopic theory and the question of (non-perturbative) renormalizability of quantum gravity.
All approaches under consideration have produced significant new results and insight in recent years and are serious candidates to fill the opening for a successful model of a quantized gravitational theory. This workshop will provide the opportunity to compare these different strategies, to identify their advantages and the challenges they face, in particular from the perspective of how space-time emerges. This will facilitate and deepen the exchange of ideas and techniques among the assorted proposals and hopefully lead to new collaborations and networking.