We analyze from a geometric perspective the Hamiltonian formulation of a recent modification of the Husain-Kucha\v{ r} 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 3-dimensional diffeomorphisms can be accommodated among the local gauge transformations of the model in addition to the internal gauge symmetries.
Categories: gr-qc math-ph math.MP