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… Expand

The phase structure of the Wick-rotated path integral in three dimensions with the aid of computer simulations is investigated, finding a whole range of the gravitational coupling constant k{sub 0} for which the functional integral is dominated by nondegenerate three-dimensional space-times.Expand

Evidence is presented that a macroscopic four-dimensional world emerges from Causal Dynamical Triangulations in four dimensions dynamically, which provides a background-independent definition of the sum over geometries in nonperturbative quantum gravity.Expand

The dynamical generation of a four-dimensional classical universe from nothing but fundamental quantum excitations at the Planck scale is a long-standing challenge to theoretical physicists. A… Expand

We measure the spectral dimension of universes emerging from nonperturbative quantum gravity, deﬁned through state sums of causal triangulated geometries. While four-dimensional on large scales, the… Expand

We show that the quantum universe emerging from a nonperturbative, Lorentzian sum over geometries can be described with a high accuracy by a four-dimensional de Sitter spacetime. By a scaling… Expand

The spectral dimension of universes emerging from nonperturbative quantum gravity is measured, defined through state sums of causal triangulated geometries, and it is concluded that quantum gravity may be "self-renormalizing" at the Planck scale, by virtue of a mechanism of dynamical dimensional reduction.Expand