{ "id": "1001.2936", "version": "v1", "published": "2010-01-18T00:31:00.000Z", "updated": "2010-01-18T00:31:00.000Z", "title": "Classification of nonorientable regular embeddings of complete bipartite graphs", "authors": [ "Jin Ho Kwak", "Young Soo Kwon" ], "categories": [ "math.CO" ], "abstract": "A 2-cell embedding of a graph $G$ into a closed (orientable or nonorientable) surface is called regular if its automorphism group acts regularly on the flags - mutually incident vertex-edge-face triples. In this paper, we classify the regular embeddings of complete bipartite graphs $K_{n,n}$ into nonorientable surfaces. Such regular embedding of $K_{n,n}$ exists only when $n = 2p_1^{a_1}p_2^{a_2}... p_k^{a_k}$ (a prime decomposition of $n$) and all $p_i \\equiv \\pm 1 (\\mod 8)$. In this case, the number of those regular embeddings of $K_{n,n}$ up to isomorphism is $2^k$.", "revisions": [ { "version": "v1", "updated": "2010-01-18T00:31:00.000Z" } ], "analyses": { "subjects": [ "05C10", "05C30" ], "keywords": [ "complete bipartite graphs", "nonorientable regular embeddings", "classification", "mutually incident vertex-edge-face triples", "prime decomposition" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }