{ "id": "2406.04559", "version": "v1", "published": "2024-06-07T00:26:36.000Z", "updated": "2024-06-07T00:26:36.000Z", "title": "The automorphism groups of small affine rank 3 graphs", "authors": [ "Jin Guo", "Andrey V. Vasil'ev", "Rui Wang" ], "categories": [ "math.CO", "math.GR" ], "abstract": "A rank 3 graph is an orbital graph of a rank 3 permutation group of even order. Despite the classification of rank 3 graphs being complete, see, e.g., Chapter 11 of the recent monograph 'Strongly regular graphs' by Brouwer and Van Maldeghem, the full automorphism groups of these graphs (equivalently, the 2-closures of rank 3 groups) have not been explicitly described, though a lot of information on this subject is available. In the present note, we address this problem for the affine rank 3 graphs. We find the automorphism groups for finitely many relatively small graphs and show that modulo known results, this provides the full description of the automorphism groups of the affine rank 3 graphs, thus reducing the general problem to the case when the socle of the automorphism group is nonabelian simple.", "revisions": [ { "version": "v1", "updated": "2024-06-07T00:26:36.000Z" } ], "analyses": { "subjects": [ "20B25", "05E18", "05E30" ], "keywords": [ "small affine rank", "monograph strongly regular graphs", "full automorphism groups", "permutation group", "nonabelian simple" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }