Analytic Results in 2D Causal Dynamical Triangulations: A Review
| dc.creator | Zohren, S. | |
| dc.date | 2006-09-25 | |
| dc.date.accessioned | 2026-07-07T07:24:17Z | |
| dc.date.available | 2026-07-07T07:24:17Z | |
| dc.description | We describe the motivation behind the recent formulation of a nonperturbative path integral for Lorentzian quantum gravity defined through Causal Dynamical Triangulations (CDT). In the case of two dimensions the model is analytically solvable, leading to a genuine continuum theory of quantum gravity whose ground state describes a two-dimensional "universe" completely governed by quantum fluctuations. One observes that two-dimensional Lorentzian and Euclidean quantum gravity are distinct. In the second part of the review we address the question of how to incorporate a sum over space-time topologies in the gravitational path integral. It is shown that, provided suitable causality restrictions are imposed on the path integral histories, there exists a well-defined nonperturbative gravitational path integral including an explicit sum over topologies in the setting of CDT. A complete analytical solution of the quantum continuum dynamics is obtained uniquely by means of a double scaling limit. We show that in the continuum limit there is a finite density of infinitesimal wormholes. Remarkably, the presence of wormholes leads to a decrease in the effective cosmological constant, reminiscent of the suppression mechanism considered by Coleman and others in the context of a Euclidean path integral formulation of four-dimensional quantum gravity in the continuum. In the last part of the review universality and certain generalizations of the original model are discussed, providing additional evidence that CDT define a genuine continuum theory of two-dimensional Lorentzian quantum gravity. | |
| dc.description | 66 pages, 17 figures. Based on the author's thesis for the Master of Science in Theoretical Physics, supervised by R. Loll and co-supervised by J. Ambjorn, J. Jersak, July 2005 | |
| dc.identifier | https://arxiv.org/abs/hep-th/0609177 | |
| dc.identifier | http://arxiv.org/abs/hep-th/0609177 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/116295 | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Analytic Results in 2D Causal Dynamical Triangulations: A Review | |
| dc.type | text |