Embedding [formula omitted] and [formula omitted] on the double torus

Abstract

The Kuratowski graphs K3,3 and K5 characterize planarity. Counting distinct 2-cell embeddings of these two graphs on orientable surfaces was previously done by Mull (1999) and Mull et al. (2008), using Burnside’s Lemma and automorphism groups of K3,3 and K5, without actually constructing the embeddings. We obtain all 2-cell embeddings of these graphs on the double torus, using a constructive approach. This shows that there is a unique non-orientable 2-cell embedding of K3,3, and 14 orientable and 17 non-orientable 2-cell embeddings of K5 on the double torus, which are explicitly obtained using an algorithmic procedure of expanding from minors. Therefore we confirm the numbers of embeddings obtained by Mull (1999) and Mull et al. (2008). As a consequence, several new polygonal representations of the double torus are presented. Rotation systems for the one-face embeddings of K5 on the triple torus are also found, using exhaustive search.