SHORT-WAVELENGTH INSTABILITY IN PRESENCE OF A ZERO MODE - ANOMALOUS GROWTH LAW

A nonlinear model that combines onset of nonoscillatory short-waveleng th instability and a long-wave zero mode is investigated numerically. Due to the coupling to the zero mode, the system's dynamics drasticall y differs from those in traditional short-wavelength models. In agreem ent with independent recently published results, we conclude that, imm ediately beyond the instability threshold, the system demonstrates a c haotic behavior, which makes it cognate to the long-wave systems. An e ssentially novel result is that a mean amplitude of the dynamical patt erns grows linearly with the overcriticality. The corresponding scalin g power 1 is just between the values 1/2 and 3/2, characteristic, resp ectively, for the traditional short- and long-wave models. (C) 1997 El sevier Science B.V.