  We study the nonlinear dynamics of the splitting of a doubly quantized vortex
in a trapped condensate. The dynamics is studied in detail by solving the
Gross-Pitaevskii equation. The main dynamical features are explained in terms
of a nonlinear three-level system. We find an analytical solution for the
characteristics of the dynamics. It is concluded that the time scale for the
splitting is mainly determined by the instability of the linearized system, and
nonlinear effects contribute logarithmically.
