N-Solitons on a Curved Vortex Filament

The motion of a thin vortex filament in an incompressible inviscid fluid is investigated theoretically, based on the localized induction equation. The N -soliton solution is given explicitly, using the bilinear equations obtained by Hirota. A detailed examination of the solution shows that two solitons with large lateral excursion suffer backward phase-shifts during a head-on collision. The present solution also generates the N -soliton solution of the classical 1-dim. continuous Heisenberg ferromagnet equation.