{ "id": "2406.04714", "version": "v1", "published": "2024-06-07T07:46:26.000Z", "updated": "2024-06-07T07:46:26.000Z", "title": "Asymptotic Expansions of the auxiliary function", "authors": [ "Juan Arias de Reyna" ], "comment": "28 pages, 3 figures", "categories": [ "math.NT" ], "abstract": "Siegel in 1932 published a paper on Riemann's posthumous writings, including a study of the Riemann-Siegel formula. In this paper we explicitly give the asymptotic developments of $\\mathop{\\mathcal R }(s)$ suggested by Siegel. We extend the range of validity of these asymptotic developments. As a consequence we specify a region in which the function $\\mathop{\\mathcal R }(s)$ has no zeros. We also give complete proofs of some of Siegel's assertions. We also include a theorem on the asymptotic behaviour of $\\mathop{\\mathcal R }(\\frac12-it)$ for $t \\to+\\infty$. Although the real part of $e^{-i\\vartheta(t)}\\mathop{\\mathcal R }(\\frac12-it)$ is $Z(t)$ the imaginary part grows exponentially, this is why for the study of the zeros of $Z(t)$ it is preferable to consider $\\mathop{\\mathcal R }(\\frac12+it)$ for $t>0$.", "revisions": [ { "version": "v1", "updated": "2024-06-07T07:46:26.000Z" } ], "analyses": { "subjects": [ "11M06", "30D99" ], "keywords": [ "auxiliary function", "asymptotic expansions", "asymptotic developments", "imaginary part grows", "riemann-siegel formula" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable" } } }