Moment ratios for absorbing-state phase transitions

TL;DR

This paper calculates moments and ratios of the order parameter in models with absorbing-state phase transitions, confirming their universality and refining critical point estimates for specific models.

Contribution

It provides a detailed analysis of moment ratios across models, confirming their universality and improving critical point estimates for the pair contact process.

Findings

Moment ratios are universal within the directed percolation class.

Refined estimate of the critical point for the pair contact process.

System-size dependence of ratios analyzed in detail.

Abstract

We determine the first through fourth moments of the order parameter, and various ratios, for several one- and two-dimensional models with absorbing-state phase transitions. We perform a detailed analysis of the system-size dependence of these ratios, and confirm that they are indeed universal for three models - the contact process, the A model, and the pair contact process - belonging to the directed percolation universality class. Our studies also yield a refined estimate for the critical point of the pair contact process.