CONTROLS
ORDER PARAMETER
Active fraction ρ: 0.000
λ_c ≈ 1/2 (μ=1)
Phase: —
STATISTICS
Step: 0
Active sites: 0
Survival prob: 0.00
The contact process is the simplest model with an absorbing state transition.
Below λ_c the epidemic dies out; above it persists. Critical exponents: β≈0.276, ν_⊥≈1.097, ν_∥≈1.734 (2D DP).
■ infected ■ recovered ■ susceptible