Authors: Brigitte Servatius and Herman Servatius
Reference: Discrete Mathematics 140 (1995) 167-183
Given a self--dual map on the sphere, the collection of its self--dual permutations generates a transformation group in which the map automorphism group appears as a subgroup of index two. A careful examination of this pairing yields direct constructions of self--dual maps and provides a classification of self--dual maps. Examples from each of the symmetry classes are given.