{ "id": "2101.05711", "version": "v1", "published": "2021-01-14T16:36:43.000Z", "updated": "2021-01-14T16:36:43.000Z", "title": "Norton algebras of the Hamming Graphs via linear characters", "authors": [ "Jia Huang" ], "comment": "27 pages, comments welcome", "categories": [ "math.CO" ], "abstract": "The Norton product is defined on each eigenspace of a distance regular graph by the orthogonal projection of the entry-wise product. The resulting algebra, known as the Norton algebra, is a commutative nonassociative algebra that is useful in group theory due to its interesting automorphism group. We provide a formula for the Norton product on each eigenspace of a Hamming graph using linear characters. We construct a large subgroup of automorphisms of the Norton algebra of a Hamming graph and completely describe the automorphism group in some cases. We also show that the Norton product on each eigenspace of a Hamming graph is as nonassociative as possible, except for some special cases in which it is either associative or equally as nonassociative as the so-called double minus operation previously studied by the author, Mickey, and Xu. Our results restrict to the hypercubes and extend to the halved and/or folded cubes, the bilinear forms graphs, and more generally, all Cayley graphs of finite abelian groups.", "revisions": [ { "version": "v1", "updated": "2021-01-14T16:36:43.000Z" } ], "analyses": { "subjects": [ "05E30", "17A36", "20B25" ], "keywords": [ "hamming graph", "norton algebra", "linear characters", "norton product", "automorphism group" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable" } } }