Critical evaluation of common claims in loop quantum cosmology

Abstract

A large number of models have been analyzed in loop quantum cosmology, using mainly minisuperspace constructions and perturbations. At the same time, general physics principles from effective field theory and covariance have often been ignored. A consistent introduction of these ingredients requires substantial modifications of existing scenarios. As a consequence, none of the broader claims made mainly by the Ashtekar school --- such as the genericness of bounces with astonishingly semiclassical dynamics, robustness with respect to quantization ambiguities, the realization of covariance, and the relevance of certain technical results for potential observations --- hold up to scrutiny. Several useful lessons for a sustainable version of quantum cosmology can be drawn from this outcome.

32 pages, invited contribution to Special Issue "Quantum Models for Cosmology"

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Cited by in corpus (39)

• A Short Review of Loop Quantum Gravity
• Unitarity, clock dependence and quantum recollapse in quantum cosmology
• A no-go result for covariance in models of loop quantum gravity
• Hybrid Loop Quantum Cosmology: An Overview
• Effective relational cosmological dynamics from Quantum Gravity
• An Overview on the Nature of the Bounce in LQC and PQM
• Quantum Oppenheimer-Snyder model
• Causal Structure of a recent Loop Quantum Gravity Black Hole Collapse Model
• Non-covariance of the dressed-metric approach in loop quantum cosmology
• Quantum dynamics of the black hole interior in LQC
• Phantom-like dark energy from quantum gravity
• Effective Quantum Dust Collapse via Surface Matching
• Phase space analysis of the bouncing universe with stringy effects
• Exteriors to bouncing collapse models
• Loop quantum gravity, signature change, and the no-boundary proposal
• Polymer dynamics of isotropic universe in Ashtekar and in volume variables
• Is Bianchi I a Bouncing Cosmology in the Wheeler-DeWitt picture?
• The Cosmological Spinor
• Big Bang Singularity Resolution In Quantum Cosmology
• Lorentzian quantum cosmology from effective spin foams
• Semiclassical and quantum features of the Bianchi I cosmology in the polymer representation
• Friedmann equations and cosmic bounce in a modified cosmological scenario
• Is the diagonal case a general picture for Loop Quantum Cosmology?
• Quasiclassical solutions for static quantum black holes
• Cosmic tangle: Loop quantum cosmology and CMB anomalies
• Fate of Mixmaster Chaos in a Deformed Algebra framework
• Cyclic spacetimes through singularity scattering maps. The laws of quiescent bounces
• The Physical Relevance of the Fiducial Cell in Loop Quantum Cosmology
• The role of spatial curvature in constraining the Universe anisotropies across a Big Bounce
• Regularization of the cosmological sector of loop quantum gravity with bosonic matter and the related problems with general covariance of quantum corrections
• Weyl Curvature Hypothesis in light of Quantum Backreaction at Cosmological Singularities or Bounces
• Bouncing Bianchi Models with Deformed Commutation Relations
• Cosmology in Loop Quantum Gravity: symmetry reduction preserving gauge degrees of freedom
• On the evolution of the volume in Loop Quantum Cosmology
• On the Role of Fiducial Structures in Minisuperspace Reduction and Quantum Fluctuations in LQC
• Cosmic tango between the very small and the very large: Addressing CMB anomalies through Loop Quantum Cosmology
• The phenomenology of Quantum Bounce in the Klein-Gordon, Wheeler-DeWitt and Dirac formalisms
• Thermodynamics of spacetime from minimal area
• Black-hole models in loop quantum gravity