title: Phase transition of a two-dimensional binary spreading model.
abstract: We investigated the phase transition behavior of a binary spreading process in two dimensions for different particle diffusion strengths (D). We found that N>2 cluster mean-field approximations must be considered to get consistent singular behavior. The N=3,4 approximations result in a continuous phase transition belonging to a single universality class along the D subset (0,1) phase transition line. Large scale simulations of the particle density confirmed mean-field scaling behavior with logarithmic corrections. This is interpreted as numerical evidence supporting the bosonic field theoretical prediction that the upper critical dimension in this model is d(c)=2. The pair density scales in a similar way but with an additional logarithmic factor to the order parameter. At the D=0 end point of the transition line we found directed percolation criticality.
authors.affiliation: Research Institute for Technical Physics and Materials Science, P. O. Box 49, H-1525 Budapest, Hungary.
authors.forename: G
authors.initials: G
authors.lastname: Odor
authors.forename: M C
authors.initials: MC
authors.lastname: Marques
authors.forename: M A
authors.initials: MA
authors.lastname: Santos