{ "id": "1508.03814", "version": "v1", "published": "2015-08-16T11:50:05.000Z", "updated": "2015-08-16T11:50:05.000Z", "title": "Differences of subgroups in subgroups", "authors": [ "Ilya D. Shkredov" ], "comment": "24 pages", "categories": [ "math.NT", "math.CO" ], "abstract": "We prove, in particular, that if A,G are two arbitrary multiplicative subgroups of the prime field f_p, |G| < p^{3/4} such that the difference A-A is contained in G then |A| \\ll |\\G|^{1/3+o(1)}. Also, we obtain that for any eps>0 and a sufficiently large subgroup G with |G| \\ll p^{1/2-eps} there is no representation G as G = A+B, where A is another subgroup, and B is an arbitrary set, |A|,|B|>1. Finally, we study the number of collinear triples containing in a set of f_p and prove a \"dual\" sum-products estimate.", "revisions": [ { "version": "v1", "updated": "2015-08-16T11:50:05.000Z" } ], "analyses": { "keywords": [ "differences", "prime field", "sufficiently large subgroup", "arbitrary multiplicative subgroups", "arbitrary set" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150803814S" } } }