Numerical dispersion

In computational mathematics, numerical dispersion is a difficulty with computer simulations of continua (such as fluids) wherein the simulated medium exhibits a higher dispersivity than the true medium. This phenomenon can be particularly egregious when the system should not be dispersive at all, for example a fluid acquiring some spurious dispersion in a numerical model. It occurs whenever the dispersion relation for the finite difference approximation is nonlinear.^[1][2] For these reasons, it is often seen as a numerical error. Numerical dispersion is often identified, linked and compared with numerical diffusion,^[3] another artifact of similar origin.