Quantisation of Extended Objects

The `strong-coupling' perturbation theory over the inverse interaction constant $1/g$ near the nontrivial solution of Lagrange equation is formulated. The ordinary `week-coupling' perturbation theory over $g$ is described also to compare both perturbation theories. The `strong-coupling' perturbation theory is developed by unitary mapping of the quantum dynamics into the space with local coordinates of (action, angle)-type.