Stable self-consistent Green´s function diakoptics without spurious recurrences

The discrete space-time-domain wave interaction between distant computational domains can efficiently be described via Green´s function diakoptics. For a toy problem with a computational domain consisting of two non-adjacent points, the inverse of the stability function facilitates the derivation of a stable unlimited lookback scheme. This approach permits the use of inter-domain continuous Green´s functions, which eliminates the problem of mesh dispersion, but sacrifices self-consistency. Discrete Green´s functions should be used if self-consistency is preferred. For a square lattice, inter-domain mesh dispersion can be suppressed by doubling the number of points per wavelength, for every factor of ten distance increase.