Critical behavior of binary production reaction-diffusion systems

摘要

Recently reaction-diffusion type of models were introduced that involve particle (or pair) production and annihilation at pairs, while lonely particles follow annihilating random walks, hence they may be described by a system with a coupled diffusive field. Different numerical studies have found that this kind of models in ld exhibit continuous phase transitions to absorbing states with new type of universal behavior for which neither bosonic field theoretical treatment nor arguments based on symmetries provided full understanding. Site restricted (fermionic) and unrestricted (bosonic) versions of these models exhibit different critical behaviors. In 2d large scale simulations (using grid network) show that mean-field type of behavior (with logarithmic corrections) emerges. In id it is debated whether the critical behavior changes by varying the diffusion rate or not. I show some recent simulation results in one and two dimensions that clarifies the situation to some extent. I give an outlook to generalizations of these models.