Coverings and structure of crossing families

Abstract

The second problem we consider is to find a compact representation of F. We prove that there exists a so-called hypercactus K of size O(|V|), consisting of cycles and (hyper)edges arranged in a tree-like manner, and a mapping from V to V(K) in such a way that there is a bijection between the minimum cuts of K and the members of F. If F corresponds to the minimum cuts of a k-edge-connected graph then K reduces to the well-known cactus representation of minimum cuts due to Dinitz et al.