{ "id": "1205.0107", "version": "v1", "published": "2012-05-01T08:13:30.000Z", "updated": "2012-05-01T08:13:30.000Z", "title": "Areas of triangles and Beck's theorem in planes over finite fields", "authors": [ "Alex Iosevich", "Misha Rudnev", "Yujia Zhai" ], "categories": [ "math.CO", "math.CA", "math.NT" ], "abstract": "It is shown that any subset $E$ of a plane over a finite field $\\F_q$, of cardinality $|E|>q$ determines not less than $\\frac{q-1}{2}$ distinct areas of triangles, moreover once can find such triangles sharing a common base. It is also shown that if $|E|\\geq 64q\\log_2 q$, then there are more than $\\frac{q}{2}$ distinct areas of triangles sharing a common vertex. The result follows from a finite field version of the Beck theorem for large subsets of $\\F_q^2$ that we prove. If $|E|\\geq 64q\\log_2 q$, there exists a point $z\\in E$, such that there are at least $\\frac{q}{4}$ straight lines incident to $z$, each supporting the number of points of $E$ other than $z$ in the interval between $\\frac{|E|}{2q}$ and $\\frac{2|E|}{q}.$ This is proved by combining combinatorial and Fourier analytic techniques. We also discuss higher-dimensional implications of these results in light of recent developments.", "revisions": [ { "version": "v1", "updated": "2012-05-01T08:13:30.000Z" } ], "analyses": { "subjects": [ "52C10" ], "keywords": [ "becks theorem", "distinct areas", "fourier analytic techniques", "finite field version", "straight lines incident" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1205.0107I" } } }