Absorbing state transition · order parameter vs noise q
Parameters
Magnetization m: —
Step: 0
Phase: —
About
Each spin adopts the majority state of its 4 neighbours with probability (1−q), or flips with noise q.
Critical noise: q_c ≈ 0.075 in 2D. Below q_c the system orders (absorbing-like ordered phase); above, disordered. The transition is in the Ising universality class.
The majority-vote model is a non-equilibrium opinion dynamics model. Each agent takes the majority opinion of its neighbours but flips with noise probability q. At q < q_c ≈ 0.075 (2D square lattice) a ferromagnetic ordered phase emerges; above q_c the system is disordered. Unlike equilibrium Ising, detailed balance is broken—yet the transition shares the same universality class.