{ "id": "2103.00882", "version": "v1", "published": "2021-03-01T10:07:46.000Z", "updated": "2021-03-01T10:07:46.000Z", "title": "k-apices of minor-closed graph classes. I. Bounding the obstructions", "authors": [ "Ignasi Sau", "Giannos Stamoulis", "Dimitrios M. Thilikos" ], "comment": "46 pages and 12 figures. arXiv admin note: text overlap with arXiv:2004.12692", "categories": [ "math.CO", "cs.DM", "cs.DS" ], "abstract": "Let ${\\cal G}$ be a minor-closed graph class. We say that a graph $G$ is a $k$-apex of ${\\cal G}$ if $G$ contains a set $S$ of at most $k$ vertices such that $G\\setminus S$ belongs to ${\\cal G}.$ We denote by ${\\cal A}_k ({\\cal G})$ the set of all graphs that are $k$-apices of ${\\cal G}.$ We prove that every graph in the obstruction set of ${\\cal A}_k ({\\cal G}),$ i.e., the minor-minimal set of graphs not belonging to ${\\cal A}_k ({\\cal G}),$ has size at most $2^{2^{2^{2^{{\\sf poly}(k)}}}},$ where ${\\sf poly}$ is a polynomial function whose degree depends on the size of the minor-obstructions of ${\\cal G}.$ This bound drops to $2^{2^{{\\sf poly}(k)}}$ when ${\\cal G}$ excludes some apex graph as a minor.", "revisions": [ { "version": "v1", "updated": "2021-03-01T10:07:46.000Z" } ], "analyses": { "subjects": [ "05C75", "05C83", "05C75", "05C69", "G.2.2", "F.2.2" ], "keywords": [ "minor-closed graph class", "bound drops", "polynomial function", "minor-minimal set", "apex graph" ], "note": { "typesetting": "TeX", "pages": 46, "language": "en", "license": "arXiv", "status": "editable" } } }