Generalized contact process with two symmetric absorbing states in two dimensions

TL;DR

This paper investigates a two-dimensional generalized contact process with two absorbing states, revealing two distinct phase transitions with different critical behaviors, including a transition consistent with the generalized voter universality class.

Contribution

It provides large-scale simulation evidence for the phase diagram and critical behavior of the generalized contact process with symmetric absorbing states in two dimensions.

Findings

Infinitesimal activation rate induces a transition to the active phase.

Critical behavior aligns with the generalized voter universality class.

Zero activation rate transition is non-critical.

Abstract

We explore the two-dimensional generalized contact process with two absorbing states by means of large-scale Monte-Carlo simulations. In part of the phase diagram, an infinitesimal creation rate of active sites between inactive domains is sufficient to take the system from the inactive phase to the active phase. The system therefore displays two different nonequilibrium phase transitions. The critical behavior of the generic transition is compatible with the generalized voter (GV) universality class, implying that the symmetry-breaking and absorbing transitions coincide. In contrast, the transition at zero domain-boundary activation rate is not critical.