Soliton complex dynamics in strongly dispersive medium

The concept of soliton complex in a nonlinear dispersive medium is proposed . It is shown that strongly interacting identical topological solitons in t he medium can form bound soliton complexes which move without radiation. Th is phenomenon is considered to be universal and applicable to various physi cal systems. The soliton complex and its "excited" states are described ana lytically and numerically as solutions of nonlinear dispersive equations wi th the fourth and higher order spatial or mixed derivatives. The dispersive sine-Gordon (dSG), double and triple sine-Gordon, and piecewise linear mod els are studied in detail. Mechanisms and conditions of the formation of so liton complexes, and peculiarities of their stationary dynamics are investi gated. A phenomenological approach to the description of the complexes and the classification of all the possible complex states are proposed. Some ex amples of physical systems, where the phenomenon can be experimentally obse rved, are briefly discussed. (C) 2001 Elsevier Science B.V. All rights rese rved.