Asymptotic behavior and noise reduction in diffusion-limited aggregation models
A generalization of the diffusion-limited aggregation (DLA) model, originally proposed by Witten and Sander [Phys. Rev. B 27, 5686 (1983)], has been studied on a very large square lattice. This model has a sticking probability p for a random walker which is assumed to depend on the number of occupied nearest-neighbor sites in the cluster B, as p=±3-B. A dynamical phase transition between growth along the axes and growth along the diagonals is observed at a critical ±c0.175. Our simulations also show that ±c changes with the amount of noise reduction. Thus we show for the first time that noise reduction may change the asymptotic behavior of DLA models. © 1989 The American Physical Society.