2
3
100
Nodes: 0
Edges: 0
Max degree: 0
Hub node: –
Edges: 0
Max degree: 0
Hub node: –
Preferential Attachment
Barabási & Albert (1999, Science): new nodes attach with prob ∝ existing degree. Produces P(k) ~ k⁻γ with γ=3. Explains WWW, citation networks, protein interactions. Scale-free: no characteristic scale — hubs dominate. The bottom plot shows log-log degree distribution; slope = −3 is the prediction.
Barabási & Albert (1999, Science): new nodes attach with prob ∝ existing degree. Produces P(k) ~ k⁻γ with γ=3. Explains WWW, citation networks, protein interactions. Scale-free: no characteristic scale — hubs dominate. The bottom plot shows log-log degree distribution; slope = −3 is the prediction.