 This algebra, sometimes called the Grossman–Larson algebra, is dual to the Connes-Kreimer algebra, which is one way of organizing the computations required when renormalizing Feynman diagrams.Working with Peter Crouch, he showed that there are Runge–Kutta methods that evolve naturally on Lie groups.From 1990–2010, he primarily worked in computer science, specifically, data mining and data intensive computing.