{ "id": "1601.07206", "version": "v1", "published": "2016-01-26T21:55:54.000Z", "updated": "2016-01-26T21:55:54.000Z", "title": "Sets in Almost General Position", "authors": [ "Luka Milićević" ], "comment": "20 pages, no figures", "categories": [ "math.CO" ], "abstract": "Erd\\H{o}s asked the following question: given $n$ points in the plane in almost general position (no 4 collinear), how large a set can we guarantee to find that is in general position (no 3 collinear)? F\\\"uredi constructed a set of $n$ points in almost general position with no more than $o(n)$ points in general position. Cardinal, T\\'oth and Wood extended this result to $\\mathbb{R}^3$, finding sets of $n$ points with no 5 on a plane whose subsets with no 4 points on a plane have size $o(n)$, and asked the question for higher dimensions: for given $n$, is it still true that the largest subset in general position we can guarantee to find has size $o(n)$? We answer their question for all $d$ and derive improved bounds for certain dimensions.", "revisions": [ { "version": "v1", "updated": "2016-01-26T21:55:54.000Z" } ], "analyses": { "keywords": [ "general position", "higher dimensions", "largest subset", "finding sets" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }