Anomaly freedom of the vector modes with holonomy corrections in   perturbative Euclidean loop quantum gravity
  We study the perturbation of the effective Hamiltonian constraint with holonomy correction from Euclidean loop quantum gravity. The Poisson bracket between the corrected Hamiltonian constraint and the diffeomorphism constraint is derived for vector modes. Some specific form of the holonomy correction function $f^{i}_{cd}$ is found, which satisfies that the constraint algebra is anomaly-free. This result confirms the possibility of non-trivial holonomy corrections from full theory while preserving anomaly-free constraint algebra in the perturbation framework. It also gives valuable hints on the possible form of holonomy corrections in effective loop quantum gravity. 
Jian-Pin Wu and Yongge Ma
gr-qc astro-ph.CO