Pair contact process with diffusion of pairs

Abstract

The pair contact process (PCP) is a nonequilibrium stochastic model which,like the basic contact process (CP), exhibits a phase transition to an absorbingstate. The two models belong to the directed percolation (DP) universality class,despite the fact that the PCP possesses infinitely many absorbing configurationswhereas the CP has but one. The critical behavior of the PCP with hoppingby particles (PCPD) is as yet unclear. Here we study a version of the PCP inwhich nearest-neighbor particle pairs can hop but individual particles cannot.Using quasistationary simulations for three values of the diffusion probability (D = 0.1,0.5 and0.9), we find convincing evidence of DP-like critical behavior.