2005/05/31 by J. Ambjorn, J. Jurkiewicz, R. Loll · 2 citations
Physics and Astronomy · #hep-th #gr-qc #hep-lat
paper · pdf · doi:10.1103/physrevd.72.064014
published as Phys.Rev.D72:064014,2005 · 52 pages, 20 postscript figures, added references
arxiv created 2005/06/06 · arxiv updated 2010/04/06
We provide detailed evidence for the claim that nonperturbative quantum gravity, defined through state sums of causal triangulated geometries, possesses a large-scale limit in which the dimension of spacetime is four and the dynamics of the volume of the universe behaves semiclassically. This is a first step in reconstructing the universe from a dynamical principle at the Planck scale, and at the same time provides a nontrivial consistency check of the method of causal dynamical triangulations. A closer look at the quantum geometry reveals a number of highly nonclassical aspects, including a dynamical reduction of spacetime to two dimensions on short scales and a fractal structure of slices of constant time.