title: Effect of diffusion in one-dimensional discontinuous absorbing phase transitions.
abstract: It is known that diffusion provokes substantial changes in continuous absorbing phase transitions. Conversely, its effect on discontinuous transitions is much less understood. In order to shed light in this direction, we study the inclusion of diffusion in the simplest one-dimensional model with a discontinuous absorbing phase transition, namely, the long-range contact process (σ-CP). Particles interact as in the usual CP, but the transition rate depends on the length ℓ of inactive sites according to 1+aℓ(-σ), where a and σ are control parameters. The inclusion of diffusion in this model has been investigated by numerical simulations and mean-field calculations. Results show that there exists three distinct regimes. For sufficiently low and large σ's the transition is, respectively, always discontinuous or continuous, independently of the strength of the diffusion. On the other hand, in an intermediate range of σ's, the diffusion causes a suppression of the phase coexistence leading to a continuous transition belonging to the directed percolation universality class.
authors.affiliation: Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, 05315-970 São Paulo, São Paulo, Brazil.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Fiore
authors.affiliation: Universidade Federal do ABC, 09210-580 Santo André, Brazil.
authors.forename: Gabriel T
authors.initials: GT
authors.lastname: Landi
mesh_terms: D004058:Diffusion; D008962:Models, Theoretical; D044367:Phase Transition