Wolfgang Hackbusch

Wolfgang Hackbusch (born 24 October 1948 in Westerstede, Lower Saxony) is a German mathematician, known for his pioneering research in multigrid methods and later hierarchical matrices, a concept generalizing the fast multipole method. He was a professor at the University of Kiel and is currently one of the directors of the Max Planck Institute for Mathematics in the Sciences in Leipzig. Provided by Wikipedia