{ "id": "1101.5278", "version": "v1", "published": "2011-01-27T13:12:28.000Z", "updated": "2011-01-27T13:12:28.000Z", "title": "Nonseparating K4-subdivisions in graphs of minimum degree at least 4", "authors": [ "Matthias Kriesell" ], "comment": "IMADA-preprint-math, 25 pages", "categories": [ "math.CO" ], "abstract": "We first prove that for every vertex x of a 4-connected graph G there exists a subgraph H in G isomorphic to a subdivision of the complete graph K4 on four vertices such that G-V(H) is connected and contains x. This implies an affirmative answer to a question of W. Kuehnel whether every 4-connected graph G contains a subdivision H of K4 as a subgraph such that G-V(H) is connected. The motor for our induction is a result of Fontet and Martinov stating that every 4-connected graph can be reduced to a smaller one by contracting a single edge, unless the graph is the square of a cycle or the line graph of a cubic graph. It turns out that this is the only ingredience of the proof where 4-connectedness is used. We then generalize our result to connected graphs of minimum degree at least 4, by developing the respective motor: A structure theorem for the class of simple connected graphs of minimum degree at least 4.", "revisions": [ { "version": "v1", "updated": "2011-01-27T13:12:28.000Z" } ], "analyses": { "keywords": [ "minimum degree", "nonseparating k4-subdivisions", "complete graph k4", "cubic graph", "line graph" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1101.5278K" } } }