2005/10/31 by Peter Grassberger · 1 citation
Physics and Astronomy · #cond-mat.stat-mech
paper · pdf · doi:10.1088/1742-5468/2006/01/p01004
10 pages, including 10 figures; accepted for JSTAT
arxiv created 2005/12/06 · arxiv updated 2009/12/01
We present detailed simulations of a generalization of the Domany-Kinzel model to 2+1 dimensions. It has two control parameters p and q which describe the probabilities Pk of a site to be wetted, if exactly k of its "upstream" neighbours are already wetted. If Pk depends only weakly on k, the active/adsorbed phase transition is in the directed percolation (DP) universality class. If, however, Pk increases fast with k so that the formation of inactive holes surrounded by active sites is suppressed, the transition is first order. These two transition lines meet at a tricritical point. This point should be in the same universality class as a tricritical transition in the contact process studied recently by Lübeck. Critical exponents for it have been calculated previously by means of the field theoretic epsilon-expansion (ε= 3-d, with d=2 in the present case). Rather poor agreement is found with either.