Hamiltonian Formalism of General Bimetric Gravity

We perform the Hamiltonian analysis of general bimetric gravity. We determine four first class constraints that are generators of the diagonal diffeomorphism. We further analyze the remaining constraints and we present an evidence that these constraints should be the second class constraints in order to have theory with the Hamiltonian constraint as the first class constraint. We also discuss the case of the non-linear bimetric gravity and argue that it is very difficult to eliminate the ghost mode.