Resolving the issue of branched Hamiltonian in modified Lanczos-Lovelock   gravity
  The Hamiltonian constraint Hc = NH = 0, defines a diffeomorphic structure on spatial manifolds by the lapse function N in general theory of relativity. However, it is not manifest in Lanczos-Lovelock gravity, since the expression for velocity in terms of the momentum is multivalued. Thus the Hamiltonian is a branch function of momentum. Here we propose an extended theory of Lanczos-Lovelock gravity to construct a unique Hamiltonian in its minisuperspace version, which results in manifest diffeomorphic invariance and canonical quantization. 
Soumendranath Ruz, Ranajit Mandal, Subhra Debnath, Abhik Kumar Sanyal
hep-th