
Clustering and Cliques in Preferential Attachment Random Graphs with Edge Insertion
Caio Alves, Rodrigo Ribeiro, Rémy Sanchis
Journal of Statistical Physics 191 (6) (2024).
Abstract
In this paper, we investigate the global clustering coefficient (a.k.a transitivity) and clique number of graphs generated by a preferential attachment random graph model with an additional feature of allowing edge connections between existing vertices. Specifically, at each time step t, either a new vertex is added with probability f(t), or an edge is added between two existing vertices with probability 1 – f(t). We establish concentration inequalities for the global clustering and clique number of the resulting graphs under the assumption that f(t) is a regularly varying function at infinity with index of regular variation –$$\gamma$$, where $$\gamma$$ $$\in$$ [0, 1). Finally, we also demonstrate an inverse relation between these two statistics: the clique number is essentially the reciprocal of the global clustering coefficient.