Multicritical behavior of the diluted contact process

TL;DR

This paper investigates the multicritical behavior of a diluted contact process on a 2D lattice, focusing on the critical point where directed and isotropic percolation phenomena intersect, using numerical simulations to explore scaling behaviors.

Contribution

It provides a detailed numerical analysis of the multicritical point in a diluted contact process, highlighting its relation to critical directed and isotropic percolation.

Findings

Identification of the multicritical point at p=1/2 and λ=3.55(1)

Discussion of possible scaling forms for critical behavior

Numerical evidence supporting the critical nature of the point

Abstract

We study a contact process on a two-dimensional square lattice which is diluted by randomly removing bonds with probability p. For p<1/2 and varying birth rate $\lambda$ the model was shown to exhibit a continuous phase transition which belongs to the universality class of strongly disordered directed percolation. The phase transition line terminates in a multicritical point at p=1/2 and $\lambda=\lambda*=3.55(1)$, where the model can be interpreted as a critical directed percolation process running on a critical isotropic percolation cluster. In the present work we study the multicritical point and its neighboorhood by numerical simulations, discussing possible scaling forms which could describe the critical behavior at the transition.