Epidemic Network
SIR model on a contact network — watch diseases percolate through social structure
The SIR model divides a population into Susceptible, Infected, and Recovered. On a network, infection spreads only along edges — so topology matters. R₀ = β/γ (here ≈ β×avg_degree/γ). Erdős–Rényi: random edges, low clustering. Watts–Strogatz: high clustering with short paths. Barabási–Albert: power-law degree distribution — a few hubs dominate and become superspreaders.