The Structure of Minimum Vertex Cuts

Abstract

In this paper we continue a long line of work on representing the cut structure of graphs. We classify the types minimum vertex cuts, and the possible relationships between multiple minimum vertex cuts. As a consequence of these investigations, we exhibit a simple $O(\kappa n)$-space data structure that can quickly answer pairwise $(\kappa +1)$-connectivity queries in a $\kappa$-connected graph. We also show how to compute the "closest" $\kappa$-cut to every vertex in near linear $\tilde{O}(m+poly(\kappa )n)$ time.