Covariance in models of loop quantum gravity: Gowdy systems

TL;DR

This paper investigates the covariance properties of polarized Gowdy models in loop quantum gravity, revealing no-go results and showing classical Abelianization of deformations, thus advancing understanding of quantum constraints in these systems.

Contribution

It derives no-go properties for covariance in polarized Gowdy models within loop quantum gravity and demonstrates classical Abelianization of deformations, highlighting limitations and structures of these models.

Findings

No-go properties for covariance in Gowdy models

Classical Abelianization of normal deformations

Insights into quantum constraint structures

Abstract

Recent results in the construction of anomaly-free models of loop quantum gravity have shown obstacles when local physical degrees of freedom are present. Here, a set of no-go properties is derived in polarized Gowdy models, raising the question whether these systems can be covariant beyond a background treatment. As a side product, it is shown that normal deformations in classical polarized Gowdy models can be Abelianized.