Dipole approximation in three vortices dynamics

The problem of mutual movement of two similar vortices (dipole pair) and a third vortex for different stream functions was solved. A partially linearized hamiltonian, corresponding to the problem of mutual movement of the dipole and monopole vortices, is studied. The problem consists in explicit description of mutual dynamics of the vortex pair and vortex Q, as well as in giving an answer to the question, when the given vortex pair resists decomposition into separate vortices. It is implied by decomposition of a vortex pair that the vortices drift apart to a distance l comparable with the distance to the central vortex R