Articulation Points in Complex Networks

TL;DR

This paper develops analytical tools to study articulation points in complex networks, revealing their role in network vulnerability and resilience, and introduces a greedy removal process linked to different percolation transitions.

Contribution

It provides a general framework for analyzing articulation points in arbitrary complex networks and explores their impact on network robustness and vulnerability.

Findings

Greedy articulation point removal reveals organizational principles.

Identifies two types of percolation transitions related to articulation points.

Results inform design of resilient infrastructure and strategies for network disruption.

Abstract

An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, e.g. the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a novel perspective on the organizational principles of complex networks. Moreover, this process is associated with two fundamentally different types of percolation transitions with a rich phase diagram. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks.