Robust Algebraic Connectivity

Abstract

The second smallest eigenvalue of the Laplacian is known as the algebraic connectivity of a graph. It shows degree of graph connectivity. However, this metric does not take into account possible changes in the graph. The removal of even one node or edge can make it disconnected. This work is devoted to the development of a metric that should describe robustness of a graph to such changes. All proposed metrics are based on the algebraic connectivity. In addition, we generalize some well-known optimization methods for our robust modifications of the algebraic connectivity. The paper also reports results of some numerical experiments demonstrating the efficiency of the proposed approaches.