Hidden diffeos in the Hamiltonian formulation of a background independent field theory

In this paper, we analyze from a geometric perspective the Hamiltonian formulation of a recent modification of the Husain–Kuchař model where, while preserving the connection as a dynamical variable, the other field is restricted to be the exterior covariant derivative of a Lie algebra-valued function. We prove that three-dimensional diffeomorphisms can be accommodated among the local gauge transformations of the model in addition to the internal gauge symmetries.