{ "id": "1907.03943", "version": "v1", "published": "2019-07-09T02:13:18.000Z", "updated": "2019-07-09T02:13:18.000Z", "title": "Congruences with intervals and arbitrary sets", "authors": [ "William Banks", "Igor Shparlinski" ], "categories": [ "math.NT" ], "abstract": "Given a prime $p$, an integer $H\\in[1,p)$, and an arbitrary set $\\cal M\\subseteq \\mathbb F_p^*$, where $\\mathbb F_p$ is the finite field with $p$ elements, let $J(H,\\cal M)$ denote the number of solutions to the congruence $$ xm\\equiv yn\\bmod p $$ for which $x,y\\in[1,H]$ and $m,n\\in\\cal M$. In this paper, we bound $J(H,\\cal M)$ in terms of $p$, $H$ and the cardinality of $\\cal M$. In a wide range of parameters, this bound is optimal. We give two applications of this bound: to new estimates of trilinear character sums and to bilinear sums with Kloosterman sums, complementing some recent results of Kowalski, Michel and Sawin (2018).", "revisions": [ { "version": "v1", "updated": "2019-07-09T02:13:18.000Z" } ], "analyses": { "keywords": [ "arbitrary set", "congruence", "trilinear character sums", "wide range", "kloosterman sums" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }