Nonlinear waves in nonequilibrium systems of the oscillatory type

Nonlinear waves in nonequilibrium spatially uniform media with the oscillatory instability of the trivial state are considered. For the short wave system, i.e., that are with the trival state unstable against perturbations with finite wave numbers, a general one dimensional wave solution is found and its stability is investigated. Collisions of these waves in one and two dimensional cases are also considered. For the long wave dispersive systems, the hypothesis is formulated that there exists the potential which makes it possible to compare the absolute stability of different quasistationary states.