Phenomenology of Quantum Reduced Loop Gravity in the isotropic cosmological sector

TL;DR

This paper explores the phenomenology of quantum reduced loop gravity in isotropic cosmology, showing it predicts sufficient inflation and analyzing primordial tensor spectra, thus connecting quantum gravity with observable cosmological features.

Contribution

It provides a detailed analysis of the isotropic sector of quantum reduced loop gravity, linking it with inflationary predictions and primordial spectra, bridging theory and observations.

Findings

Number of inflationary e-folds exceeds observational lower bounds.

Primordial tensor power spectrum is sensitive to fundamental parameters.

The model offers a consistent quantum gravity framework for early universe phenomenology.

Abstract

Quantum reduced loop gravity is designed to consistently study symmetry reduced systems within the loop quantum gravity framework. In particular, it bridges the gap between the effective cosmological models of loop quantum cosmology and the full theory, addressing the dynamics before the minisuperspace reduction. This mostly preserves the graph structure and SU(2) quantum numbers. In this article, we study the phenomenological consequences of the isotropic sector of the theory, the so-called emergent bouncing universe model. In particular, the parameter space is scanned and we show that the number of inflationary e-folds is almost always higher than the observational lower-bound. We also compute the primordial tensor power spectrum and study its sensitivity upon the fundamental parameters used in the model.