Radiation boundary conditions for dispersive waves

The author develops radiation boundary conditions for the numerical modeling of dispersive waves. During the construction of such boundary conditions, the goal is to simulate the outward radiation of waves near an artificial computational boundary. The velocities of the outgoing waves are typically involved in processes of this nature. A central problem in the dispersive case is that two different types of velocities are present, phase velocity and group velocity, and each can vary with wavenumber and frequency. With the boundary conditions developed in this paper, the user needs to specify some parameters; in the cases that are emphasized here, the parameters can be interpreted in terms of phase velocities of waves that are absorbed exactly at the computational boundary. The amount of reflected error is a continuous function of the parameters, and the performance of the boundary conditions is not sensitive to the choice of parameters. Good performance is obtained in numerical tests involving data that ha...