{ "id": "2408.16733", "version": "v1", "published": "2024-08-29T17:25:58.000Z", "updated": "2024-08-29T17:25:58.000Z", "title": "Erdős-Pósa property of tripods in directed graphs", "authors": [ "Marcin Briański", "Meike Hatzel", "Karolina Okrasa", "Michał Pilipczuk" ], "comment": "12 pages, 4 figures", "categories": [ "math.CO", "cs.DM" ], "abstract": "Let $D$ be a directed graphs with distinguished sets of sources $S\\subseteq V(D)$ and sinks $T\\subseteq V(D)$. A tripod in $D$ is a subgraph consisting of the union of two $S$-$T$-paths that have distinct start-vertices and the same end-vertex, and are disjoint apart from sharing a suffix. We prove that tripods in directed graphs exhibit the Erd\\H{o}s-P\\'osa property. More precisely, there is a function $f\\colon \\mathbb{N}\\to \\mathbb{N}$ such that for every digraph $D$ with sources $S$ and sinks $T$, if $D$ does not contain $k$ vertex-disjoint tripods, then there is a set of at most $f(k)$ vertices that meets all the tripods in $D$.", "revisions": [ { "version": "v1", "updated": "2024-08-29T17:25:58.000Z" } ], "analyses": { "keywords": [ "directed graphs", "erdős-pósa property", "distinct start-vertices", "disjoint apart", "vertex-disjoint tripods" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }