NONINTEGRABLE 3-MODE INTERACTION IN THE ZAKHAROV-EQUATIONS

In this paper we investigate the behavior of an interacting wave tripl et in the context of the Zakharov equations. As the amplitude of the c arrier modes grows, the nonlinear modulational frequency with which th ey exchange energy becomes comparable to their linear high frequencies - in this situation adiabatic approximations can no longer be used. I n fact, we find that while for small amplitudes the tripler is approxi mately integrable and yields almost periodic solutions, for larger amp litudes it develops fully nonintegrable features characteristic of str ong chaotic regimes. An appropriate Hamiltonian formalism is developed to describe the dynamics.