Multigrid methods for computation of magnetostatic fields in magnetic recording problems

Calculation of magnetostatic fields is usually the most time-consuming stag e of micromagnetic simulations. In this article, the Bramble-Pasciak-Xu mul tilevel preconditioners (MP) are applied to the computation of magnetostati c fields in media such as magnetic tapes or thin films. The asymptotic numb er of arithmetic operations is optimal and proportional to the number of no des in the finite element mesh. Unlike the fast Fourier transform, MP are a pplicable to irregular meshes. Local (adaptive) mesh refinement can be impl emented by switching to the hierarchical basis. (C) 1998 American Institute of Physics. [S0021-8979(98)38311-5].