Abstract: | We derive an asymptotic expression for the evolution of stationary beams in strongly nonlinear three-dimensional media. Formulas are obtained for the distribution of the beam amplitude and phase velocity, and effectively solvable equations are constructed for the beam axial line. It is shown that with power-function nonlinearity, the determination of the beam axial line is separated from the determination of the field concentrated near this line.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 148, pp. 52–60, 1985. |