{ "id": "1308.4321", "version": "v1", "published": "2013-08-20T14:38:17.000Z", "updated": "2013-08-20T14:38:17.000Z", "title": "On Obstacle Numbers", "authors": [ "Vida Dujmović", "Pat Morin" ], "categories": [ "math.CO", "cs.CG", "cs.DM" ], "abstract": "The obstacle number is a new graph parameter introduced by Alpert, Koch, and Laison (2010). Mukkamala etal (2012) show that there exist graphs with n vertices having obstacle number in Omega(n/\\log n). In this note, we up this lower bound to Omega(n/(\\log\\log n)^2. Our proof makes use of an upper bound of Mukkamala etal on the number of graphs having obstacle number at most h in such a way that any subsequent improvements to their upper bound will improve our lower bound.", "revisions": [ { "version": "v1", "updated": "2013-08-20T14:38:17.000Z" } ], "analyses": { "keywords": [ "obstacle number", "mukkamala etal", "lower bound", "upper bound", "graph parameter" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1308.4321D" } } }