{ "id": "1303.3457", "version": "v1", "published": "2013-03-14T14:28:28.000Z", "updated": "2013-03-14T14:28:28.000Z", "title": "Groups whose prime graphs have no triangles", "authors": [ "Hung P. Tong-Viet" ], "comment": "13 pages", "journal": "Journal of Algebra 378 (2013), 196-206", "doi": "10.1016/j.jalgebra.2012.12.024", "categories": [ "math.GR", "math.CO", "math.RT" ], "abstract": "Let G be a finite group and let cd(G) be the set of all complex irreducible character degrees of G Let \\rho(G) be the set of all primes which divide some character degree of G. The prime graph \\Delta(G) attached to G is a graph whose vertex set is \\rho(G) and there is an edge between two distinct primes u and v if and only if the product uv divides some character degree of G. In this paper, we show that if G is a finite group whose prime graph \\Delta(G) has no triangles, then \\Delta(G) has at most 5 vertices. We also obtain a classification of all finite graphs with 5 vertices and having no triangles which can occur as prime graphs of some finite groups. Finally, we show that the prime graph of a finite group can never be a cycle nor a tree with at least 5 vertices.", "revisions": [ { "version": "v1", "updated": "2013-03-14T14:28:28.000Z" } ], "analyses": { "subjects": [ "20C15", "05C25" ], "keywords": [ "prime graph", "finite group", "complex irreducible character degrees", "product uv divides", "vertex set" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1303.3457T" } } }