{ "id": "2005.10714", "version": "v1", "published": "2020-05-21T15:11:16.000Z", "updated": "2020-05-21T15:11:16.000Z", "title": "Small values of $| L^\\prime/L(1,χ) |$", "authors": [ "Youness Lamzouri", "Alessandro Languasco" ], "comment": "20 pages, 3 figures, 1 table", "categories": [ "math.NT" ], "abstract": "In this paper, we investigate the quantity $m_q:=\\min_{\\chi\\ne \\chi_0} | L^\\prime/L(1,\\chi)|$, as $q\\to \\infty$ over the primes, where $L(s,\\chi)$ is the Dirichlet $L$-function attached to a non trivial Dirichlet character modulo $q$. Our main result shows that $m_q \\ll \\log\\log q/\\sqrt{\\log q}$. We also compute $m_q$ for every odd prime $q$ up to $10^7$. As a consequence we numerically verified that for every odd prime $q$, $3 \\le q \\le 10^7$, we have $c_1/q< m_q<5/\\sqrt{q}$, with $c_1=21/200$. In particular, this shows that $L^\\prime(1,\\chi) \\ne 0$ for every non trivial Dirichlet character $\\chi$ mod $q$ where $3\\leq q\\leq 10^7$ is prime, answering a question of Gun, Murty and Rath in this range. We also provide some statistics and scatter plots regarding the $m_q$-values, see Section 6. The programs used and the computational results described here are available at the following web address: \\url{http://www.math.unipd.it/~languasc/smallvalues.html}.", "revisions": [ { "version": "v1", "updated": "2020-05-21T15:11:16.000Z" } ], "analyses": { "subjects": [ "11E45", "11M41" ], "keywords": [ "small values", "non trivial dirichlet character modulo", "odd prime", "web address", "computational results" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }