{ "id": "math/0112146", "version": "v1", "published": "2001-12-14T08:20:45.000Z", "updated": "2001-12-14T08:20:45.000Z", "title": "On the Expansion of Graphs of 0/1-Polytopes", "authors": [ "Volker Kaibel" ], "comment": "19 pages", "categories": [ "math.CO", "math.PR" ], "abstract": "The edge expansion of a graph is the minimum quotient of the number of edges in a cut and the size of the smaller one among the two node sets separated by the cut. Bounding the edge expansion from below is important for bounding the ``mixing time'' of a random walk on the graph from above. It has been conjectured by Mihail and Vazirani that the graph of every 0/1-polytope has edge expansion at least one. A proof of this (or even a weaker) conjecture would imply solutions of several long-standing open problems in the theory of randomized approximate counting. We present different techniques for bounding the edge expansion of a 0/1-polytope from below. By means of these tools we show that several classes of 0/1-polytopes indeed have graphs with edge expansion at least one. These classes include all 0/1-polytopes of dimension at most five, all simple 0/1-polytopes, all hypersimplices, all stable set polytopes, and all (perfect) matching polytopes.", "revisions": [ { "version": "v1", "updated": "2001-12-14T08:20:45.000Z" } ], "analyses": { "subjects": [ "52B12", "52B11", "52B05", "68W20", "60G50" ], "keywords": [ "edge expansion", "minimum quotient", "stable set polytopes", "node sets", "long-standing open problems" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2001math.....12146K" } } }