We prove explicitly that to every discrete, semibounded Hamiltonian with
constant degeneracy and with finite sum of the squares of the reciprocal of its
eigenvalues and whose eigenvectors span the entire Hilbert space there exists a
characteristic self-adjoint time operator which is canonically conjugate to the
Hamiltonian in a dense subspace of the Hilbert space. Moreover, we show that
each characteristic time operator generates an uncountable class of self-
adjoint operators canonically conjugate with the same Hamiltonian in the same
dense subspace.Comment: accepted for publication in the Proceedings of the Royal Society of
London