{ "id": "1608.06398", "version": "v1", "published": "2016-08-23T06:46:38.000Z", "updated": "2016-08-23T06:46:38.000Z", "title": "An improvement on the number of simplices in $\\mathbb{F}_q^d$", "authors": [ "Thang Pham", "Duc Hiep Pham", "Anh Vinh Le" ], "categories": [ "math.CO" ], "abstract": "Let $\\mathcal{E}$ be a set of points in $\\mathbb{F}_q^d$. Bennett, Hart, Iosevich, Pakianathan, and Rudnev (2016) proved that if $|\\mathcal{E}|\\gg q^{d-\\frac{d-1}{k+1}}$ then $\\mathcal{E}$ determines a positive proportion of all $k$-simplices. In this paper, we give an improvement of this result in the case when $\\mathcal{E}$ is the Cartesian product of sets. More precisely, we show that if $\\mathcal{E}$ is the Cartesian product of sets and $q^{\\frac{kd}{k+1-1/d}}=o(|\\mathcal{E}|)$, the number of congruence classes of $k$-simplices determined by $\\mathcal{E}$ is at least $(1-o(1))q^{\\binom{k+1}{2}}$, and in some cases our result is sharp.", "revisions": [ { "version": "v1", "updated": "2016-08-23T06:46:38.000Z" } ], "analyses": { "keywords": [ "improvement", "cartesian product", "congruence classes", "determines", "pakianathan" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }