{ "id": "1907.00513", "version": "v1", "published": "2019-07-01T02:06:06.000Z", "updated": "2019-07-01T02:06:06.000Z", "title": "Elementary Proof of a Theorem of Hawkes, Isaacs and Özaydin", "authors": [ "Matthé van der Lee" ], "comment": "9 pages", "categories": [ "math.GR", "math.CO", "math.NT" ], "abstract": "We present an elementary proof of the theorem of Hawkes, Isaacs and \\\"Ozaydin, which states that $\\Sigma\\,\\mu_{G}(H,K)\\equiv 0$ mod $d$, where $\\mu_{G}$ denotes the M\\\"obius function for the subgroup lattice of a finite group $G$, $H$ ranges over the conjugates of a given subgroup $F$ of $G$ with $[G:F]$ divisible by $d$, and $K$ over the supergroups of the $H$ for which $[K:H]$ divides $d$. We apply the theorem to obtain a result on the number of solutions of $|\\langle H,g\\rangle|\\mid n$, for said $H$ and a natural number $n$.", "revisions": [ { "version": "v1", "updated": "2019-07-01T02:06:06.000Z" } ], "analyses": { "subjects": [ "20D30", "11A25", "05E15" ], "keywords": [ "elementary proof", "finite group", "natural number", "subgroup lattice", "supergroups" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable" } } }