Conversion of long-range calculations to short-range calculations in micromagnetic problems

The computation of long-range interactions in micromagnetic problems is very time-consuming, since they must be computed and summed for each pair of calculation and source points; furthermore, this calculation has to be done at each iteration of the micromagnetic calculation. A technique is presented which replaces the necessary integration by the solution of a differential equation using Dirichlet boundary conditions. A comparison of this method with the integration technique is presented.