{ "id": "2302.02725", "version": "v1", "published": "2023-02-06T12:07:33.000Z", "updated": "2023-02-06T12:07:33.000Z", "title": "Congruence classes for modular forms over small sets", "authors": [ "Subham Bhakta", "S. Krishnamoorthy", "R. Muneeswaran" ], "comment": "23 pages", "categories": [ "math.NT" ], "abstract": "J.P. Serre showed that for any integer $m,~a(n)\\equiv 0 \\pmod m$ for almost all $n,$ where $a(n)$ is the $n^{\\text{th}}$ Fourier coefficient of any modular form with rational coefficients. In this article, we consider a certain class of cuspforms and study $\\#\\{a(n) \\pmod m\\}_{n\\leq x}$ over the set of integers with $O(1)$ many prime factors. Moreover, we show that any residue class $a\\in \\mathbb{Z}/m\\mathbb{Z}$ can be written as the sum of at most thirteen Fourier coefficients, which are polynomially bounded as a function of $m.$", "revisions": [ { "version": "v1", "updated": "2023-02-06T12:07:33.000Z" } ], "analyses": { "subjects": [ "11F30", "11L07", "11P05", "11B37", "11F80" ], "keywords": [ "modular form", "small sets", "congruence classes", "rational coefficients", "prime factors" ], "note": { "typesetting": "TeX", "pages": 23, "language": "en", "license": "arXiv", "status": "editable" } } }