{ "id": "1205.4060", "version": "v2", "published": "2012-05-17T23:23:14.000Z", "updated": "2013-04-22T12:00:01.000Z", "title": "Dense flag triangulations of 3-manifolds via extremal graph theory", "authors": [ "Michal Adamaszek", "Jan Hladky" ], "comment": "Trans. AMS, to appear", "categories": [ "math.CO" ], "abstract": "We characterize f-vectors of sufficiently large three-dimensional flag Gorenstein* complexes, essentially confirming a conjecture of Gal [Discrete Comput. Geom., 34 (2), 269--284, 2005]. In particular, this characterizes f-vectors of large flag triangulations of the 3-sphere. Actually, our main result is more general and describes the structure of closed flag 3-manifolds which have many edges. Looking at the 1-skeleta of these manifolds we reduce the problem to a certain question in extremal graph theory. We then resolve this question by employing the Supersaturation Theorem of Erdos and Simonovits.", "revisions": [ { "version": "v2", "updated": "2013-04-22T12:00:01.000Z" } ], "analyses": { "keywords": [ "extremal graph theory", "dense flag triangulations", "sufficiently large three-dimensional flag", "large flag triangulations", "characterizes f-vectors" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1205.4060A" } } }