Fig. 2From: Replicator equation on networks with degree regular communitiesPrisoner’s dilemma, death-birth Fraction of cooperators in equilibrium as the graph structure change. The graph has three communities, k=3, k=4, k=5. The benefit-cost ratio is b/c=10/3, so when average degree is more than 10/3 defection prevails. The plot also shows few cases where cooperators and defectors coexist in equilibriumBack to article page