Voter Model — Interface Density Coarsening (1D)

In the 1D voter model, each site adopts the opinion of a random neighbor at each step. Domains coarsen algebraically in time as interfaces perform random walks and annihilate on meeting. The interface density ρ(t) ~ t⁻¹/² — a hallmark of coarsening dynamics without surface tension.

Controls
Theory
Interface density:
ρ(t) ~ t⁻¹/²
Coarsening exponent
z = 2 (diffusive)
In 1D: consensus
reached in O(N²) steps