{ "id": "2006.15661", "version": "v1", "published": "2020-06-28T17:33:25.000Z", "updated": "2020-06-28T17:33:25.000Z", "title": "Non-vanishing for cubic $L$--functions", "authors": [ "Chantal David", "Alexandra Florea", "Matilde Lalin" ], "comment": "53 pages", "categories": [ "math.NT" ], "abstract": "We prove that there is a positive proportion of $L$-functions associated to cubic characters over $\\mathbb{F}_q[T]$ that do not vanish at the critical point $s=1/2$. This is achieved by computing the first mollified moment using techniques previously developed by the authors in their work on the first moment of cubic $L$-functions, and by obtaining a sharp upper bound for the second mollified moment, building on work of Lester-Radziwill, which in turn develops further ideas from the work of Soundararajan, Harper, and Radziwill-Soundararajan. We work in the non-Kummer setting when $q \\equiv 2\\pmod{3}$, but our results could be translated into the Kummer setting when $q\\equiv 1\\pmod{3}$ as well as into the number field case (assuming the Generalized Riemann Hypothesis). Our positive proportion of non-vanishing is explicit, but extremely small, due to the fact that the implied constant in the upper bound for the mollified second moment is very large.", "revisions": [ { "version": "v1", "updated": "2020-06-28T17:33:25.000Z" } ], "analyses": { "keywords": [ "non-vanishing", "positive proportion", "sharp upper bound", "number field case", "first moment" ], "note": { "typesetting": "TeX", "pages": 53, "language": "en", "license": "arXiv", "status": "editable" } } }