IDENTIFICATION OF MASS CAPTURING STRUCTURES IN A PERTURBED NONLINEAR SCHRODINGER-EQUATION

The numerical solutions of a standard damped and driven nonlinear Schr odinger equation are compared with a systematic reduction obtained by the Kahunen-Loeve expansion. The role of the mass-containing modes is clarified by analyzing the spectral data of the underlying periodic di rect problem. A one-to-one correspondence to the marginally stable mod es obtained from the linearized Backlund transformation is found, whic h explains the observed low-dimensional behavior.