Sociomeeting: Universality of noise-induced transitions in nonlinear voter models

The paradigmatic voter model is a simple agent-based model of opinion formation in a population of interacting agents that imitate each other at random. While this classical model lacks a phase transition due to the absence of a control parameter, its nonlinear and noisy generalizations exhibit richer critical behavior. In this work we address two questions. First, we classify the universality classes of the phase transitions in several nonlinear voter models within a general model that encompasses the universality classes of critical phenomena observed in systems with

two absorbing state. Second, we investigate the universality classes of the noise-induced transitions of noisy nonlinear voter models, where absorbing states are absent. We propose a generalization of the canonical model previously studied that includes all these models. Using finite-size scaling techniques across regular lattices, complete graphs, and complex networks, we show that the noise-induced transitions of these models belong to the Ising universality class, with some models displaying tricritical points with mean-field characteristics.