{ "id": "1904.04065", "version": "v1", "published": "2019-04-05T10:00:30.000Z", "updated": "2019-04-05T10:00:30.000Z", "title": "On the Regions Formed by the Diagonals of a Convex Polygon", "authors": [ "C P Anil Kumar" ], "comment": "25 pages, 7 figures", "categories": [ "math.CO" ], "abstract": "For a positive integer $n\\geq 3$, the sides and diagonals of a convex $n$-gon divide the interior of the convex $n$-gon into finitely (polynomial in $n$) many regions bounded by them. Here in this article we associate to every region a unique $n$-cycle in the symmetric group $S_n$ of a certain type (defined as two standard consecutive cycle) by studying point arrangements in the plane. Then we find that there are more (exponential in $n$) number of such cycles leading to the conclusion that not every region labelled by a cycle appears in every convex $n$-gon. In fact most of them do not occur in any given single convex $n$-gon. Later in main Theorem $\\Omega$ of this article we characterize combinatorially those cycles (defined as definite cycles) whose corresponding regions occur in every convex $n$-gon and those cycles (defined as indefinite cycles) whose corresponding regions do not occur in every convex $n$-gon.", "revisions": [ { "version": "v1", "updated": "2019-04-05T10:00:30.000Z" } ], "analyses": { "subjects": [ "51D20", "52C35" ], "keywords": [ "convex polygon", "main theorem", "single convex", "corresponding regions occur", "indefinite cycles" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable" } } }