{ "id": "1406.7326", "version": "v1", "published": "2014-06-27T22:08:06.000Z", "updated": "2014-06-27T22:08:06.000Z", "title": "Bounding sums of the Möbius function over arithmetic progressions", "authors": [ "Lynnelle Ye" ], "comment": "29 pages; undergraduate thesis version", "categories": [ "math.NT" ], "abstract": "Let $M(x)=\\sum_{1\\le n\\le x}\\mu(n)$ where $\\mu$ is the M\\\"obius function. It is well-known that the Riemann Hypothesis is equivalent to the assertion that $M(x)=O(x^{1/2+\\epsilon})$ for all $\\epsilon>0$. There has been much interest and progress in further bounding $M(x)$ under the assumption of the Riemann Hypothesis. In 2009, Soundararajan established the current best bound of \\[ M(x)\\ll\\sqrt{x}\\exp\\left((\\log x)^{1/2}(\\log\\log x)^c\\right) \\] (setting $c$ to $14$, though this can be reduced). Halupczok and Suger recently applied Soundararajan's method to bound more general sums of the M\\\"obius function over arithmetic progressions, of the form \\[ M(x;q,a)=\\sum_{\\substack{n\\le x \\\\ n\\equiv a\\pmod{q}}}\\mu(n). \\] They were able to show that assuming the Generalized Riemann Hypothesis, $M(x;q,a)$ satisfies \\[ M(x;q,a)\\ll_{\\epsilon}\\sqrt{x}\\exp\\left((\\log x)^{3/5}(\\log\\log x)^{16/5+\\epsilon}\\right) \\] for all $q\\le\\exp\\left(\\frac{\\log 2}2\\lfloor(\\log x)^{3/5}(\\log\\log x)^{11/5}\\rfloor\\right)$, with $a$ such that $(a,q)=1$, and $\\epsilon>0$. In this paper, we improve Halupczok and Suger's work to obtain the same bound for $M(x;q,a)$ as Soundararajan's bound for $M(x)$ (with a $1/2$ in the exponent of $\\log x$), with no size or divisibility restriction on the modulus $q$ and residue $a$.", "revisions": [ { "version": "v1", "updated": "2014-06-27T22:08:06.000Z" } ], "analyses": { "subjects": [ "11N56" ], "keywords": [ "arithmetic progressions", "möbius function", "bounding sums", "current best bound", "generalized riemann hypothesis" ], "tags": [ "dissertation" ], "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1406.7326Y" } } }