Some physical implications of regularization ambiguities in SU(2) gauge-invariant loop quantum cosmology

2019/08/31 by Klaus Liegener, Parampreet Singh · 2 citations
Physics and Astronomy · #Artificial intelligence #Black Holes and Theoretical Physics #Computer science #Cosmology #Cosmology and Gravitation Theories #Dimensional regularization #Gauge theory #Invariant (physics) #Loop quantum cosmology #Mathematical physics #Noncommutative and Quantum Gravity Theories #Physics #Quantum #Quantum cosmology #Quantum gravity #Quantum mechanics #Regularization (linguistics) #Renormalization #Special unitary group #Theoretical physics #astro-ph.CO #gr-qc #hep-th

paper · pdf · doi:10.1103/physrevd.100.124049

published as Phys. Rev. D 100, 124049 (2019) · 31 pages, 10 figures. References and a figure added. To appear in PRD

arxiv created 2019/11/14 · openalex publication_date 2019/12/19 · arxiv updated 2019/12/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06

Abstract

The way physics of loop quantum gravity is affected by the underlying quantization ambiguities is an open question. We address this issue in the context of loop quantum cosmology using gauge-covariant fluxes. Consequences are explored for two choices of regularization parameters: \ensuremathμ₀ and \ensuremathμ in the presence of a positive cosmological constant, and two choices of regularizations of the Hamiltonian constraint in loop quantum cosmology: the standard and the Thiemann regularization. We show that novel features of singularity resolution and bounce, occurring due to gauge-covariant fluxes, exist also for Thiemann-regularized dynamics. The \ensuremathμ₀ scheme is found to be unviable as in standard loop quantum cosmology when a positive cosmological constant is included. Our investigation brings out a surprising result that the nature of emergent matter in the prebounce regime is determined by the choice of regulator in the Thiemann regularization of the scalar constraint whether or not one uses gauge-covaraint fluxes. Unlike the \ensuremathμ scheme where the emergent matter is a cosmological constant, the emergent matter in the \ensuremathμ₀ scheme behaves as a string gas.

Citations

• Algebraic quantum gravity (AQG): I. Conceptual setup
• Isotropic loop quantum cosmology
• Algebraic quantum gravity (AQG): II. Semiclassical analysis
• Quantum Nature of the Big Bang
• Loop quantum cosmology and inhomogeneities
• New Variables for Classical and Quantum Gravity
• New Hamiltonian formulation of general relativity
• Is loop quantization in cosmology unique?
• Republication of: The dynamics of general relativity
• Quantization of diffeomorphism invariant theories of connections with local degrees of freedom
• Lattice refining loop quantum cosmology, anisotropic models, and stability
• Loop quantum dynamics of the Schwarzschild interior
• Stability of the Schwarzschild interior in loop quantum gravity
• Refined Algebraic Quantization: Systems with a single constraint
• New loop quantum cosmology modifications from gauge-covariant fluxes

Cited by

• New loop quantum cosmology modifications from gauge-covariant fluxes
• Twisted geometries coherent states for loop quantum gravity