{ "id": "1906.09718", "version": "v1", "published": "2019-06-24T04:27:21.000Z", "updated": "2019-06-24T04:27:21.000Z", "title": "Lower bound for class number and a proof of Chowla and Yokoi's conjecture", "authors": [ "Mohit Mishra" ], "comment": "21 pages. Comments are welcome", "categories": [ "math.NT" ], "abstract": "Let $d$ be a square-free positive integer and $h(d)$ the class number of the real quadratic field $\\mathbb{Q}{(\\sqrt{d})}.$ In this paper we give an explicit lower bound for $h(n^2+r)$, where $r=1,4$, and also establish an equivalent criteria to attain this lower bound in terms of special value of Dedekind zeta function. Our bounds enables us to provide a new proof of a well-known conjecture of Chowla and that of Yokoi. Also applying our results, we obtain some criteria for class group of prime power order to be cyclic.", "revisions": [ { "version": "v1", "updated": "2019-06-24T04:27:21.000Z" } ], "analyses": { "subjects": [ "11R29", "11R42", "11R11" ], "keywords": [ "class number", "yokois conjecture", "real quadratic field", "explicit lower bound", "dedekind zeta function" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }