An adaptive algebraic multigrid algorithm for micromagnetism

We present an adaptive algebraic multigrid algorithm. The method is intended for large sparse matrix equations that arise from finite-element discretizations of the stray field in three-dimensional micromagnetism on nonuniform or unstructured grids. It uses a varying threshold value to control the grid ratio, trying to optimize the overall efficiency of the algebraic multigrid solver. We present numerical results and compare them with the preconditioned conjugate gradient method.