{ "id": "2103.15404", "version": "v1", "published": "2021-03-29T08:00:46.000Z", "updated": "2021-03-29T08:00:46.000Z", "title": "Outerspatial 2-complexes: Extending the class of outerplanar graphs to three dimensions", "authors": [ "Johannes Carmesin", "Tsvetomir Mihaylov" ], "categories": [ "math.CO" ], "abstract": "We introduce the class of outerspatial 2-complexes as the natural generalisation of the class of outerplanar graphs to three dimensions. Answering a question of O-joung Kwon, we prove that a locally 2-connected 2-complex is outerspatial if and only if it does not contain a surface of positive genus as a subcomplex and does not have a space minor that is a generalised cone over $K_4$ or $K_{2,3}$. This is applied to nested plane embeddings of graphs; that is, plane embeddings constrained by conditions placed on a set of cycles of the graph.", "revisions": [ { "version": "v1", "updated": "2021-03-29T08:00:46.000Z" } ], "analyses": { "subjects": [ "05C83", "05C10", "05E45" ], "keywords": [ "outerplanar graphs", "outerspatial", "dimensions", "natural generalisation", "o-joung kwon" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }