{ "id": "2007.09204", "version": "v1", "published": "2020-07-17T19:42:15.000Z", "updated": "2020-07-17T19:42:15.000Z", "title": "Edge-critical subgraphs of Schrijver graphs II: The general case", "authors": [ "Tomáš Kaiser", "Matěj Stehlík" ], "categories": [ "math.CO" ], "abstract": "We give a simple combinatorial description of an $(n-2k+2)$-chromatic edge-critical subgraph of the Schrijver graph $\\mathrm{SG}(n,k)$, itself an induced vertex-critical subgraph of the Kneser graph $\\mathrm{KG}(n,k)$. This extends the main result of [J. Combin. Theory Ser. B 144 (2020) 191--196] to all values of $k$, and sharpens the classical results of Lov\\'asz and Schrijver from the 1970s.", "revisions": [ { "version": "v1", "updated": "2020-07-17T19:42:15.000Z" } ], "analyses": { "subjects": [ "05C15" ], "keywords": [ "schrijver graph", "general case", "simple combinatorial description", "chromatic edge-critical subgraph", "kneser graph" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }