Dressed metric predictions revisited

Abstract

It was recently shown that the volume operator of loop quantum cosmology (LQC) and all its positive powers are ill-defined on physical states. In this paper, we investigate how it effects predictions of cosmic microwave background (CMB) power spectra obtained within dressed metric approach for which expectations values of $\hat{a}$ are the key element. We find that almost every step in the procedure is ill-defined and relies heavily upon a (seemingly premature) numerical truncation. Thus, it suggests that more care is needed in making predictions regarding pre-inflationary physics. We propose a new scheme which contains only well-defined quantities. The surprising agreement of the hitherto models with observational data, especially at low angular momenta $l$ is explained.

arXiv comment9 pages

References in corpus (11)

• Quantum Nature of the Big Bang: Improved dynamics
• Robustness of key features of loop quantum cosmology
• The pre-inflationary dynamics of loop quantum cosmology: Confronting quantum gravity with observations
• A Quantum Gravity Extension of the Inflationary Scenario
• Quantum field theory on a cosmological, quantum space-time
• Detailed analysis of the predictions of loop quantum cosmology for the primordial power spectra
• Further Improvements in the Understanding of Isotropic Loop Quantum Cosmology
• Phenomenological investigation of a quantum gravity extension of inflation with the Starobinsky potential
• Prescriptions in Loop Quantum Cosmology: A comparative analysis
• Inflation with the Starobinsky potential in Loop Quantum Cosmology
• The volume operator in loop quantum cosmology

Cited by in corpus (11)

• Critical evaluation of common claims in loop quantum cosmology
• Black Hole evaporation: A Perspective from Loop Quantum Gravity
• Primordial power spectrum from the dressed metric approach in loop cosmologies
• Phenomenological implications of modified loop cosmologies: an overview
• Loop quantum cosmology: relation between theory and observations
• Nonexistence of quantum black and white hole horizons in an improved dynamic approach
• Universal properties of the evolution of the Universe in modified loop quantum cosmology
• On the improved dynamics approach in loop quantum black holes
• Quantum geometric formulation of Brans-Dicke theory for Bianchi I spacetime
• Cosmic tango between the very small and the very large: Addressing CMB anomalies through Loop Quantum Cosmology
• On the evolution of the volume in Loop Quantum Cosmology