{ "id": "1104.3909", "version": "v1", "published": "2011-04-20T00:31:23.000Z", "updated": "2011-04-20T00:31:23.000Z", "title": "Fermat quotients: Exponential sums, value set and primitive roots", "authors": [ "Igor E. Shparlinski" ], "doi": "10.1112/blms/bdr058", "categories": [ "math.NT" ], "abstract": "For a prime $p$ and an integer $u$ with $\\gcd(u,p)=1$, we define Fermat quotients by the conditions $$ q_p(u) \\equiv \\frac{u^{p-1} -1}{p} \\pmod p, \\qquad 0 \\le q_p(u) \\le p-1. $$ D. R. Heath-Brown has given a bound of exponential sums with $N$ consecutive Fermat quotients that is nontrivial for $N\\ge p^{1/2+\\epsilon}$ for any fixed $\\epsilon>0$. We use a recent idea of M. Z. Garaev together with a form of the large sieve inequality due to S. Baier and L. Zhao, to show that on average over $p$ one can obtain a nontrivial estimate for much shorter sums starting with $N\\ge p^{\\epsilon}$. We also obtain lower bounds on the image size of the first $N$ consecutive Fermat quotients and use it to prove that there is a positive integer $n\\le p^{3/4 + o(1)}$ such that $q_p(n)$ is a primitive root modulo $p$.", "revisions": [ { "version": "v1", "updated": "2011-04-20T00:31:23.000Z" } ], "analyses": { "subjects": [ "11A07", "11L40", "11N35" ], "keywords": [ "exponential sums", "value set", "consecutive fermat quotients", "large sieve inequality", "define fermat quotients" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1104.3909S" } } }