Coordinate time dependence in Quantum Gravity

Abstract

The intuitive classical space-time picture breaks down in quantum gravity, which makes a comparison and the development of semiclassical techniques quite complicated. Using ingredients of the group averaging method to solve constraints one can nevertheless introduce a classical coordinate time into the quantum theory, and use it to investigate the way a semiclassical continuous description emerges from discrete quantum evolution. Applying this technique to test effective classical equations of loop cosmology and their implications for inflation and bounces, we show that the effective semiclassical theory is in good agreement with the quantum description even at short scales.

35 pages, 17 figure. Revised version. To appear in Phys. Rev. D

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Cited by in corpus (26)

• Loop Quantum Cosmology
• Spherically Symmetric Quantum Geometry: Hamiltonian Constraint
• Loop cosmological dynamics and dualities with Randall-Sundrum braneworlds
• A black hole mass threshold from non-singular quantum gravitational collapse
• On the Hamiltonian Constraint of Loop Quantum Cosmology
• Effective approach to the problem of time: general features and examples
• Large scale effective theory for cosmological bounces
• Semi-classical States, Effective Dynamics and Classical Emergence in Loop Quantum Cosmology
• Effective Constraints for Quantum Systems
• Effective State Metamorphosis in Semi-Classical Loop Quantum Cosmology
• Dynamics of Quintom and Hessence Energies in Loop Quantum Cosmology
• Numerical loop quantum cosmology: an overview
• On the Physical Hilbert Space of Loop Quantum Cosmology
• The Dark Side of a Patchwork Universe
• Perturbative Degrees of Freedom in Loop Quantum Gravity: Anisotropies
• Von-Neumann Stability and Singularity Resolution in Loop Quantized Schwarzschild Black Hole
• Constraints on a scale invariant power spectrum from superinflation in LQC
• Degenerate Configurations, Singularities and the Non-Abelian Nature of Loop Quantum Gravity
• Inverse volume corrections from loop quantum gravity and the primordial tensor power spectrum in slow-roll inflation
• Minimal spatio-temporal extent of events, neutrinos, and the cosmological constant problem
• The Early Universe in Loop Quantum Cosmology
• Quantum Geometry and its Implications for Black Holes
• An Inhomogeneous Space-Time Patching Model Based on a Nonlocal and Nonlinear Schrodinger Equation
• Universe scenarios from loop quantum cosmology
• Phenomenological implications of an alternative Hamiltonian constraint for quantum cosmology
• On the Green's function and iterative solutions of Loop Quantum Cosmology