The propagation of lower hybrid waves in the presence of ponderomotive density fluctuations is considered. The problem is treated in two dimensions and, in order to be able to correctly impose the boundary conditions, the waves are allowed to evolve in time. The fields are described by ivτ − ∫ vξ dζ+vζζ + |v| v = 0 where v is proportional to the electric field, τ to time, and ζ and ξ measure di...