{ "id": "1911.13284", "version": "v1", "published": "2019-11-29T18:36:54.000Z", "updated": "2019-11-29T18:36:54.000Z", "title": "On the diameters of McKay graphs for finite simple groups", "authors": [ "Martin W. Liebeck", "Aner Shalev", "Pham Huu Tiep" ], "categories": [ "math.GR", "math.RT" ], "abstract": "Let $G$ be a finite group, and $\\alpha$ a nontrivial character of $G$. The McKay graph ${\\mathcal M}(G,\\alpha)$ has the irreducible characters of $G$ as vertices, with an edge from $\\chi_1$ to $\\chi_2$ if $\\chi_2$ is a constituent of $\\alpha\\chi_1$. We study the diameters of McKay graphs for simple groups $G$. For $G$ a group of Lie type, we show that for any $\\alpha$, the diameter is bounded by a quadratic function of the rank, and obtain much stronger bounds for $G={\\rm PSL}_n(q)$ or ${\\rm PSU}_n(q)$. We also bound the diameter for symmetric and alternating groups.", "revisions": [ { "version": "v1", "updated": "2019-11-29T18:36:54.000Z" } ], "analyses": { "subjects": [ "20C15", "20C30", "20C33" ], "keywords": [ "finite simple groups", "mckay graph", "nontrivial character", "finite group", "lie type" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }