Closed universes in two dimensional gravity
arXiv:2402.00098 · doi:10.21468/SciPostPhys.17.2.051
Abstract
We study closed universes in simple models of two dimensional gravity, such as Jackiw-Teiteilboim (JT) gravity coupled to matter, and a toy topological model that captures the key features of the former. We find there is a stark contrast, as well as some connections, between the perturbative and non-perturbative aspects of the theory. We find rich semi-classical physics. However, when non-perturbative effects are included there is a unique closed universe state in each theory. We discuss possible meanings and interpretations of this observation.
v1: 25+16 pages, 13 figures; v2: references added; v3: published version