Reconstructing the universe

By J. Ambjørn, J. Jurkiewicz, R. Loll. 2005

389 citations recorded by the source corpus.

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.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/2a41d5ed01076187590f837789f93861d8d2635a

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In Astronomy and Astrophysics

In Nuclear and High Energy Physics

In Statistical and Nonlinear Physics

Citations in the corpus

Spectral dimension of the universe in quantum gravity at a lifshitz point. (2009, neutral): “Contents”
Spectral dimension of the universe (2005, background): “space and time, with large-scale four-dimensional scaling properties [5, 7].”
The universe from scratch (2005, background): “y in Euclidean DT [31]. 24Further, independent evidence that the volumes V space(τ) of the spatial slices also scale canonically as N 4 is increased, V space ∼ N 3/DH 4 , with D H =4, can be found in [9]. 20 enables us to make contact with (quantum) cosmology. Recall the remarkable fact that almost ”
Quantum gravity from causal dynamical triangulations: a review (2019, background): “ short distances, which are dominated by lattice artefacts, the spectral dimension determined in this way is D e ˇ1:5 in phase CdS, in agreement with earlier measurements using the return probability [11,97]. As illustrated by Fig. 19, the same approximately constant value is found in phase A, where”
Cosmology of the Lifshitz universe (2009, methodology): “This is the same effective action found in CDT at large scales [39, 41]: SCDT = −SE ∼ SFRW(λ < 1/3) .”
Nonperturbative quantum gravity (2012, methodology): “What we observe in the simulations [77, 78] is that for the range of discrete volumes N4 under study the universe does not extend (i.”
Nonperturbative quantum de Sitter universe (2008, background): “8.”
Colored Group Field Theory (2009, background): “GFT’s arise naturally in several discrete approaches to quantum gravity, like Regge calculus [11], dynamical triangulations [12,13] or spin foam models [14,15] (see also [16] for further details).”
Quantum-Spacetime Phenomenology (2008, background): “I share the view of many quantum-spacetime phenomenologists who are looking at the approach based on causal dynamical triangulations [45, 371, 46, 47, 372, 49] as a maturing opportunity for inspiring the phenomenology work.”