%0 Journal Article %T Finite-gap Solutions of the Vortex Filament Equation: Isoperiodic Deformations %A Annalisa M. Calini %A Thomas A. Ivey %J Physics %D 2006 %I arXiv %R 10.1007/s00332-007-9002-x %X We study the topology of quasiperiodic solutions of the vortex filament equation in a neighborhood of multiply covered circles. We construct these solutions by means of a sequence of isoperiodic deformations, at each step of which a real double point is "unpinched" to produce a new pair of branch points and therefore a solution of higher genus. We prove that every step in this process corresponds to a cabling operation on the previous curve, and we provide a labelling scheme that matches the deformation data with the knot type of the resulting filament. %U http://arxiv.org/abs/nlin/0612065v1