A contact process with mobile disorder
Dickman, Ronald; Dickman, Ronald; Departamento de Física and National Institute of Science and Technology for Complex Systems, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, CP 702, 30123-970, Belo Horizonte, Minas Gerais, Brazil
Журнал:
Journal of Statistical Mechanics: Theory and Experiment
Дата:
2009-08-01
Аннотация:
I study the absorbing-state phase transition in the one-dimensional contact process with mobile disorder. In this model the dilution sites, though permanently inactive, diffuse freely, exchanging positions with the other sites, which host a basic contact process. Even though the disorder variables are not quenched, the critical behavior is affected: the critical exponents δ and z, the ratio and the moment ratio m = ⟨ρ<sup>2</sup>⟩/ρ<sup>2</sup> take values different from those of directed percolation, and appear to vary with the vacancy diffusion rate. While the survival probability starting from a single active seed follows the usual scaling, P(t)∼t<sup>−δ</sup>, at the critical point, the mean number of active sites and mean square spread grow more slowly than power laws. The critical creation rate increases with the vacancy density v and diverges at a value v<sub>c</sub><1. The scaling behavior at this point appears to be simpler than for smaller vacancy densities.
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