Voter Model — Coarsening to Consensus

Each agent adopts a randomly chosen neighbor's opinion. In 2D, the coarsening time scales as T ~ L² log L. Interface density decays as ρ(t) ~ 1/(t log t). Consensus (absorbing state) is reached in finite systems, driven by fluctuations — not selection.

100
2
0.000
8
t=0 interface density=1.00 consensus: none