An edge variant of the Erdős–Pósa property
Résumé
For every r ∈ N, we denote by θ r the multigraph with two vertices and r parallel edges. Given a graph G, we say that a subgraph H of G is a model of θ r in G if H contains θ r as a contraction. We prove that the following edge variant of the Erdős–Pósa property holds for every r 2: if G is a graph and k is a positive integer, then either G contains a packing of k mutually edge-disjoint models of θ r , or it contains a set S of f r (k) edges such that G \ S has no θ r-model, for both f r (k) = O(k 2 r 3 polylog kr) and f r (k) = O(k 4 r 2 polylog kr).
Domaines
Mathématiques [math]Origine | Fichiers produits par l'(les) auteur(s) |
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