Towards an anomaly-free quantum dynamics for a weak coupling limit of Euclidean gravity: Diffeomorphism covariance

Abstract

The GNewton→0 limit of Euclidean gravity introduced by Smolin is described by a generally covariant U(1)3 gauge theory. In an earlier paper, Tomlin and Varadarajan constructed the quantum Hamiltonian constraint of density weight 4/3 for this U(1)3 theory so as to produce a nontrivial anomaly-free loop quantum gravity type representation of the Poisson bracket between a pair of Hamiltonian constraints. These constructions involved a choice of regulating coordinate patches. The use of these coordinate patches is in apparent conflict with spatial diffeomorphism covariance. In this work we show how an appropriate choice of coordinate patches together with suitable modifications of these constructions results in the diffeomorphism covariance of the continuum limit action of the Hamiltonian constraint operator, while preserving the anomaly-free property of the continuum limit action of its commutator.