{ "id": "1910.04931", "version": "v1", "published": "2019-10-11T01:32:01.000Z", "updated": "2019-10-11T01:32:01.000Z", "title": "On the automorphism groups of graphs with twice prime valency", "authors": [ "Hong Ci Liao", "Jing Jian Li", "Zai Ping Lu" ], "comment": "14 pages", "categories": [ "math.CO" ], "abstract": "A graph is edge-transitive if its automorphism group acts transitively on the edge set. In this paper, we investigate the automorphism groups of edge-transitive graphs of odd order and twice prime valency. Let $\\Gamma$ be a connected graph of odd order and twice prime valency, and let $G$ be a subgroup of the automorphism group of $\\Ga$. In the case where $G$ acts transitively on the edges and quasiprimitively on the vertices of $\\Ga$, we prove that either $G$ is almost simple or $G$ is a primitive group of affine type. If further $G$ is an almost simple primitive group then, with two exceptions, the socle of $G$ acts transitively on the edges of $\\Gamma$.", "revisions": [ { "version": "v1", "updated": "2019-10-11T01:32:01.000Z" } ], "analyses": { "subjects": [ "05C25", "20B25" ], "keywords": [ "twice prime valency", "odd order", "automorphism group acts", "edge set", "affine type" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }