Universal `winner-takes-it-all' phenomenon in scale-free random graphs

TL;DR

This paper demonstrates that in scale-free random graphs with infinite variance degree distributions, a competition process leads to a universal 'winner-takes-it-all' outcome, where one type dominates almost entirely.

Contribution

It extends the 'winner-takes-it-all' phenomenon to scale-free graphs with infinite variance degrees, generalizing previous results and simplifying proofs.

Findings

The winning type occupies all but finitely many vertices.

The phenomenon holds universally across various distributions.

Simplifies understanding of competition dynamics in complex networks.

Abstract

We study competition on scale-free random graphs, where the degree distribution satisfies an asymptotic power-law with infinite variance. Our competition process is such that the two types attempt at occupying vertices incident to the presently occupied sets, and the passage times are independent and identically distributed, possibly with different distributions for the two types. Once vertices are occupied by a type, they remain on being so. We focus on the explosive setting, where our main result shows that the winning type occupies all but a finite number of vertices. This universal `winner-takes-it-all' phenomenon significantly generalises previous work with Deijfen for exponential edge-weights, and considerably simplifies its proof.