Hamiltonian dynamics of finite-gap configurations of relativistic strings

Classical dynamics of the Nambu–Goto string is investigated by means of the auxiliary spectral problem method. Lorentz invariant spectral data are derived and the action–angle variables are constructed using these data. The Poisson bracket for the components of vectors determining string configurations on finite-gap orbits is calculated and the expression for the bracket is brought to an explicitely covariant form. Geometrical interpretation of the topological charge of the string is suggested.