{ "id": "1803.01931", "version": "v1", "published": "2018-03-05T21:22:10.000Z", "updated": "2018-03-05T21:22:10.000Z", "title": "Structure and generation of crossing-critical graphs", "authors": [ "Zdeněk Dvořák", "Petr Hliněný", "Bojan Mohar" ], "categories": [ "math.CO" ], "abstract": "We study c-crossing-critical graphs, which are the minimal graphs that require at least c edge-crossings when drawn in the plane. For c=1 there are only two such graphs without degree-2 vertices, K_5 and K_3,3, but for any fixed c>1 there exist infinitely many c-crossing-critical graphs. It has been previously shown that c-crossing-critical graphs have bounded path-width and contain only a bounded number of internally disjoint paths between any two vertices. We expand on these results, providing a more detailed description of the structure of crossing-critical graphs. On the way towards this description, we prove a new structural characterisation of plane graphs of bounded path-width. Then we show that every c-crossing-critical graph can be obtained from a c-crossing-critical graph of bounded size by replicating bounded-size parts that already appear in narrow \"bands\" or \"fans\" in the graph. This also gives an algorithm to generate all the c-crossing-critical graphs of at most given order n in polynomial time per each generated graph.", "revisions": [ { "version": "v1", "updated": "2018-03-05T21:22:10.000Z" } ], "analyses": { "keywords": [ "generation", "bounded path-width", "study c-crossing-critical graphs", "polynomial time", "internally disjoint paths" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }