ИСТИНА

n a recent series of papers we constructed asymptotic formulas for spatially-periodic focusing Nonlinear Schrodinger equation under assumption that the Cauchy data is a small perturbation of an unstable background. Such solutions are used as models for generation of rogue waved in non-linear systems. Due to the fact that the spectral curves are close to rational ones, all ingredients of the theta-functional formulas can be explicitly calculated in the leading order. These asymptotic solutions are expressed in terms of elementary functions and provide a good approximation for the exact ones. In the present work we construct analogous formulas for the focusing Davey-Stewardson 2 equation, which is a 2+1 dimensional integrable analog of the Nonlinear Schrodinger equation, admitting rogue waves type solutions.