{ "id": "1009.1106", "version": "v1", "published": "2010-09-06T17:59:28.000Z", "updated": "2010-09-06T17:59:28.000Z", "title": "On a Generalization of the Flag Complex Conjecture of Charney and Davis", "authors": [ "Kestutis Cesnavicius" ], "comment": "14 pages, 10 figures", "categories": [ "math.CO" ], "abstract": "The Flag Complex Conjecture of Charney and Davis states that for a simplicial complex $S$ which triangulates a $(2n - 1)$-generalized homology sphere as a flag complex one has $(-1)^n \\sum_{\\sigma \\in S} \\left(\\frac{-1}{2}\\right)^{\\dim\\sigma + 1} \\ge 0$, where the sum runs over all simplices $\\sigma$ of $S$ (including the empty simplex). Interpreting the $1$-skeleta of $\\sigma\\in S$ as graphs of Coxeter groups, we present a stronger version of this conjecture, and prove the equivalence of the latter to the Flag Complex Conjecture.", "revisions": [ { "version": "v1", "updated": "2010-09-06T17:59:28.000Z" } ], "analyses": { "subjects": [ "05E45", "20F55" ], "keywords": [ "flag complex conjecture", "generalization", "davis states", "stronger version", "coxeter groups" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1009.1106C" } } }