Quantum Gravity, or The Art of Building Spacetime
arXiv:hep-th/0604212
Abstract
The method of four-dimensional Causal Dynamical Triangulations provides a background-independent definition of the sum over geometries in quantum gravity, in the presence of a positive cosmological constant. We present the evidence accumulated to date that a macroscopic four-dimensional world can emerge from this theory dynamically. Using computer simulations we observe in the Euclidean sector a universe whose scale factor exhibits the same dynamics as that of the simplest mini-superspace models in quantum cosmology, with the distinction that in the case of causal dynamical triangulations the effective action for the scale factor is not put in by hand but obtained by integrating out {\it in the quantum theory} the full set of dynamical degrees of freedom except for the scale factor itself.
22 pages, 6 figures. Contribution to the book "Approaches to Quantum Gravity", ed. D. Oriti, Cambridge University Press
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- Emergent Models for Gravity: an Overview of Microscopic Models
- Aspects of noncommutative (1+1)-dimensional black holes
- Infinite order quantum-gravitational correlations
- De Sitter Universe from Causal Dynamical Triangulations without Preferred Foliation
- (1+1)-Dimensional Entropic Gravity
- Primordial Black Hole Evaporation and Spontaneous Dimensional Reduction
- How to Wick rotate generic curved spacetime
- Stochastic quantization and the role of time in quantum gravity
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- A geometric construction of the Riemann scalar curvature in Regge calculus
- Horizon of quantum black holes in various dimensions
- Space as a low-temperature regime of graphs
- Correlation Measure Equivalence in Dynamic Causal Structures of Quantum Gravity
- A causal perspective on random geometry
- Singular General Relativity
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- Network Gravity
- Energetics of the Quantum Graphity Universe
- Quantum Spacetime, from a Practitioner's Point of View
- A note on the spinor construction of Spin Foam amplitudes
- Modelling gravity on a hyper-cubic lattice
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- General Formulation of Topos Many-Node Theory
- A Reasonable Ab Initio Cosmological Constant Without Holography