DYNAMICS OF OVERLAPPING VORTICES IN COMPLEX SCALAR FIELDS

We investigate dynamics of overlapping: vortices in the nonlinear Schr odinger equation, the nonlinear heat equation and in the equation with an intermediate Schrodinger-diffusion dynamics. Because of formal sim ilarity on a perturbative level we discuss also the nonlinear wave equ ation (Goldstone model). Special solutions are found like vortex helic es, double-helices and braids, breather states and vortex mouths. A pa ir of vortices in the Goldstone model scatters by the right angle in t he head-on collision. It is found that in a dissipative system there i s a characteristic length scale above which vortices can be entangled but below which the entanglement is unstable.