Connectivity transitions in networks with super-linear preferential attachment

Abstract

We analyze an evolving network model of Krapivsky and Redner in which new nodes arrive sequentially, each connecting to a previously existing node b with probability proportional to the p-th power of the in-degree of b. We restrict to the super-linear case p>1. When 1+1/k< p \leq 1 + 1/(k-1) the structure of the final countable tree is determined. There is a finite tree T with distinguished v (which has a limiting distribution) on which is "glued" a specific infinite tree. v has an infinite number of children, an infinite number of which have k-1 children, and there are only a finite number of nodes (possibly only v) with k or more children. Our basic technique is to embed the discrete process in a continuous time process using exponential random variables, a technique that has previously been employed in the study of balls-in-bins processes with feedback.