Non-covariance of "covariant polymerization" in models of loop quantum gravity

Abstract

It is possible to implement a certain form of modified gravity inspired by loop quantization through non-bijective canonical transformations. The canonical nature might suggest that such modifications are guaranteed to preserve general covariance. Here, however, we show that a dedicated space-time analysis is still required, even in the case of a bijective canonical transformation. In addition, a complete global analysis is presented for a recent proposal of a non-bijective transformation, showing that it does not preserve general covariance and that the only novel physical effect introduced by the modification is the presence of certain time-reversal hypersurfaces between classical space-time regions. These results provide further insights into the physical interpretation of modified dynamics in models of loop quantum gravity.

15 pages, v2: new extended example of a bijective canonical transformation

References in corpus (6)

• Anomaly-free cosmological perturbations in effective canonical quantum gravity
• A no-go result for covariance in models of loop quantum gravity
• Spherically symmetric canonical quantum gravity
• Linking loop quantum gravity quantization ambiguities with phenomenology
• A new look at scalar perturbations in loop quantum cosmology: (un)deformed algebra approach using self dual variables
• Deformed covariance in spherically symmetric vacuum models of loop quantum gravity: Consistency in Euclidean and self-dual gravity

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• Comment on "Towards a quantum notion of covariance in spherically symmetric loop quantum gravity"
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• Emergent Modified Gravity
• Lorentzian quantum cosmology from effective spin foams
• Inequivalence of mimetic gravity with models of loop quantum gravity
• Space-time physics in background-independent theories of quantum gravity
• Stellar collapse with pressure in effective loop quantum gravity
• Generic features of a polymer quantum black hole
• Thermodynamics of effective loop quantum black holes
• Non-singular naked solutions in quantum spacetime
• Lessons for loop quantum gravity from emergent modified gravity
• Nonsingular spherically symmetric black-hole model with holonomy corrections
• Singularities in loop quantum cosmology