{ "id": "1603.09041", "version": "v1", "published": "2016-03-30T05:16:17.000Z", "updated": "2016-03-30T05:16:17.000Z", "title": "Genera and minors of multibranched surfaces", "authors": [ "Shosaku Matsuzaki", "Makoto Ozawa" ], "comment": "23 pages, 16 figures", "categories": [ "math.GT", "math.AT", "math.CO" ], "abstract": "We say that a $2$-dimensional CW complex is a multibranched surface if we remove all points whose open neighborhoods are homeomorphic to the $2$-dimensional Euclidean space, then we obtain a $1$-dimensional complex which is homeomorphic to a disjoint union of some $S^1$'s. We define the genus of a multibranched surface $X$ as the minimum number of genera of $3$-dimensional manifold into which $X$ can be embedded. We prove some inequalities which give upper bounds for the genus of a multibranched surface. A multibranched surface is a generalization of graphs. Therefore, we can define \"minors\" of multibranched surfaces analogously. We study various properties of the minors of multibranched surfaces.", "revisions": [ { "version": "v1", "updated": "2016-03-30T05:16:17.000Z" } ], "analyses": { "keywords": [ "multibranched surface", "dimensional cw complex", "dimensional euclidean space", "upper bounds", "open neighborhoods" ], "note": { "typesetting": "TeX", "pages": 23, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160309041M" } } }