Symmetry Reduced Loop Quantum Gravity: A Bird's Eye View

Abstract

This is a brief overview of the current status of symmetry reduced models in Loop Quantum Gravity (LQG), focussing on the very early universe. Over the last 3 years or so the subject has matured sufficiently to make direct contact with observations of the Cosmic Microwave Background (CMB). In particular, thanks to an unforeseen interplay between the ultraviolet features of quantum geometry and the infrared properties of quantum fields representing cosmological perturbations, \emph{Planck scale effects} of LQG can leave imprints on CMB \emph{at the largest angular scales}. In addition to a summary of these results, the article also contains a critical discussion of the symmetry reduction procedure used in discussions of quantum cosmology (and quantum black holes).

25 pages, 2 figures. References updated; typos corrected. The abstract is expanded for readers who may not see the special volume of the journal in which this article will appear

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Cited by in corpus (9)

• Quantum Extension of the Kruskal Space-time
• Quantum Gravity in the Sky: Interplay between fundamental theory and observations
• Preinflationary dynamics in loop quantum cosmology: Monodromy Potential
• Inflation in Loop Quantum Cosmology
• Analysis of the $B^{+}\to J/\psi \varphi K^{+}$ data at low $J/\psi \varphi$ invariant masses and the $X(4140)$ and $X(4160)$ resonances
• On the UV dimensions of Loop Quantum Gravity
• Holonomy and inverse-triad corrections in spherical models coupled to matter
• Background dynamics of pre-inflationary scenario in Brans-Dicke loop quantum cosmology
• Testing general covariance in effective models motivated by Loop Quantum Gravity