{ "id": "1103.5457", "version": "v2", "published": "2011-03-28T19:50:25.000Z", "updated": "2011-05-17T13:19:55.000Z", "title": "Combinatorics of embeddings", "authors": [ "Sergey A. Melikhov" ], "comment": "49 pages, 1 figure. Minor improvements in v2 (subsection 4.C on transforms of dichotomial spheres reworked to include more details; subsection 2.D \"Algorithmic issues\" added, etc)", "categories": [ "math.GT", "math.CO" ], "abstract": "We offer the following explanation of the statement of the Kuratowski graph planarity criterion and of 6/7 of the statement of the Robertson-Seymour-Thomas intrinsic linking criterion. Let us call a cell complex 'dichotomial' if to every cell there corresponds a unique cell with the complementary set of vertices. Then every dichotomial cell complex is PL homeomorphic to a sphere; there exist precisely two 3-dimensional dichotomial cell complexes, and their 1-skeleta are K_5 and K_{3,3}; and precisely six 4-dimensional ones, and their 1-skeleta all but one graphs of the Petersen family. In higher dimensions n>2, we observe that in order to characterize those compact n-polyhedra that embed in S^{2n} in terms of finitely many \"prohibited minors\", it suffices to establish finiteness of the list of all (n-1)-connected n-dimensional finite cell complexes that do not embed in S^{2n} yet all their proper subcomplexes and proper cell-like combinatorial quotients embed there. Our main result is that this list contains the n-skeleta of (2n+1)-dimensional dichotomial cell complexes. The 2-skeleta of 5-dimensional dichotomial cell complexes include (apart from the three joins of the i-skeleta of (2i+2)-simplices) at least ten non-simplicial complexes.", "revisions": [ { "version": "v2", "updated": "2011-05-17T13:19:55.000Z" } ], "analyses": { "subjects": [ "57Q35", "57M15", "57M20", "05C83", "05C10" ], "keywords": [ "dichotomial cell complexes", "cell-like combinatorial quotients", "kuratowski graph planarity criterion", "embeddings", "n-dimensional finite cell complexes" ], "note": { "typesetting": "TeX", "pages": 49, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1103.5457M" } } }