Quantum cosmology from quantum gravity condensates: cosmological variables and lattice-refined dynamics

Abstract

In the context of group field theory condensate cosmology, we clarify the extraction of cosmological variables from the microscopic quantum gravity degrees of freedom. We show that an important implication of the second quantized formalism is the dependence of cosmological variables and equations on the quantum gravitational atomic number N (number of spin network vertices/elementary simplices). We clarify the relation of the effective cosmological equations with loop quantum cosmology, understood as an effective (hydrodynamic-like) approximation of a more fundamental quantum gravity theory. By doing so, we provide a fundamental basis to the idea of lattice refinement, showing the dependence of the effective cosmological connection on N, and hence indirectly on the scale factor. Our results open a new arena for exploring effective cosmological dynamics, as this depends crucially on the new observable N, which is entirely of quantum gravitational origin.

7 pages, APS style, revtex; v2: small changes in presentation, results unchanged, matches journal version

References in corpus (10)

• Quantum Nature of the Big Bang: Improved dynamics
• Random tensor models in the large N limit: Uncoloring the colored tensor models
• Towards Spinfoam Cosmology
• Lattice refining loop quantum cosmology, anisotropic models and stability
• Quantum cosmology of (loop) quantum gravity condensates: An example
• Loop quantum cosmology from group field theory
• Dynamical Quantum Geometry (DQG Programme)
• Non-linear (loop) quantum cosmology
• Effective equations for GFT condensates from fidelity
• Reply to `Comment on "Quantum Bounce and Cosmic Recall"' [arXiv:0811.2790]

Cited by in corpus (7)

• Functional Renormalisation Group Approach for Tensorial Group Field Theory: a Rank-3 Model
• Group field theories for all loop quantum gravity
• Nonlocal Scalar Quantum Field Theory from Causal Sets
• Dimensional flow in discrete quantum geometries
• Renormalization of an Abelian Tensor Group Field Theory: Solution at Leading Order
• Perturbing a quantum gravity condensate
• Modeling effective FRW cosmologies with perfect fluids from states of the hybrid quantum Gowdy model