Fast Algorithms for Slow Processes in Lattice-Gas Cellular Automata

The accurate numerical study of long-time tails in time-correlation functions requires large amounts of computer time. In some cases, the necessary calculations are too time-consuming to be carried out even on present-day (super)computers. However, if we consider 'lattice-gas' versions of the same problems, then it turns out that for certain problems, a speed-up of 6-10 orders of magnitude can be achieved using a very simple algorithm. As a result, we can now test theoretical (mode-coupling) predictions for long-time tails with unprecedented accuracy.