{ "id": "2003.09750", "version": "v1", "published": "2020-03-21T20:55:45.000Z", "updated": "2020-03-21T20:55:45.000Z", "title": "Large cycles in essentially 4-connected graphs", "authors": [ "Michael Wigal", "Xingxing Yu" ], "comment": "17 pages, 4 figures", "categories": [ "math.CO" ], "abstract": "Tutte proved that every 4-connected planar graph contains a Hamilton cycle, but there are 3-connected $n$-vertex planar graphs whose longest cycles have length $\\Theta(n^{\\log_32})$. On the other hand, Jackson and Wormald in 1992 proved that an essentially 4-connected $n$-vertex planar graph contains a cycle of length at least $(2n+4)/5$, which was recently improved to $5(n+2)/8$ by Fabrici {\\it et al}. In this paper, we improve this bound to $\\lceil (2n+6)/3\\rceil$ for $n\\ge 6$, which is best possible, by proving a quantitative version of a result of Thomassen on Tutte paths.", "revisions": [ { "version": "v1", "updated": "2020-03-21T20:55:45.000Z" } ], "analyses": { "subjects": [ "05C38", "05C40", "05C45" ], "keywords": [ "large cycles", "vertex planar graph contains", "longest cycles", "tutte paths", "hamilton cycle" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }