We investigate the critical behavior of a model that mimics the propagation of an epidemic process over a population mediated by a density of diffusive individuals which can infect a static population upon contact. We simulate the above model on finite chains to determine the critical density of...

We studied two models of three-species two-particle diffusion-limited reactions with and without a drift. Model A involves annihilations A+B→0, B+C→0, and C+A→0 with hard-core interactions between like species, and assumes equal initial densities of the species. The density decays...