Loop quantum gravity corrections to gravitational wave dispersion

TL;DR

This paper derives quantum gravity corrections to gravitational wave dispersion relations within loop quantum gravity, demonstrating that causality is preserved due to anomaly-free effective constraints.

Contribution

It introduces a Hamiltonian cosmology framework incorporating loop quantum gravity effects into gravitational wave dispersion analysis.

Findings

Quantum corrections modify gravitational wave dispersion relations.

Causality is maintained due to anomaly-free constraint algebra.

Framework provides a basis for quantum gravity phenomenology in cosmology.

Abstract

Cosmological tensor perturbations equations are derived for Hamiltonian cosmology based on Ashtekar's formulation of general relativity, including typical quantum gravity effects in the Hamiltonian constraint as they are expected from loop quantum gravity. This translates to corrections of the dispersion relation for gravitational waves. The main application here is the preservation of causality which is shown to be realized due to the absence of anomalies in the effective constraint algebra used.