{ "id": "0812.4562", "version": "v1", "published": "2008-12-24T20:08:45.000Z", "updated": "2008-12-24T20:08:45.000Z", "title": "Shellable Complexes from Multicomplexes", "authors": [ "Jonathan Browder" ], "comment": "12 pages", "categories": [ "math.CO" ], "abstract": "Suppose a group $G$ acts properly on a simplicial complex $\\Gamma$. Let $l$ be the number of $G$-invariant vertices and $p_1, p_2, ... p_m$ be the sizes of the $G$-orbits having size greater than 1. Then $\\Gamma$ must be a subcomplex of $\\Lambda = \\Delta^{l-1}* \\partial \\Delta^{p_1-1}*... * \\partial \\Delta^{p_m-1}$. A result of Novik gives necessary conditions on the face numbers of Cohen-Macaulay subcomplexes of $\\Lambda$. We show that these conditions are also sufficient, and thus provide a complete characterization of the face numbers of these complexes.", "revisions": [ { "version": "v1", "updated": "2008-12-24T20:08:45.000Z" } ], "analyses": { "subjects": [ "05E99" ], "keywords": [ "shellable complexes", "multicomplexes", "face numbers", "invariant vertices", "simplicial complex" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0812.4562B" } } }