How symmetric can maps on surfaces be?

Abstract

a map, that is, a cellular embeding of a gaph on a surface, may admit symmetries such as rotations and reflections. Prominent examples of maps with a 'high level of symmetry' come from Platonic and Archimedean solids. The theory of maps and their symmetries is surprisingly rich and interacts with other disciplines in mathematics such as algebraic topology, group theory, hyperbolic geometry, the theory of Riemann surfaces and Galois theory. In the first half of the paper we outline the fundamentals of the algebraic theory of regular and orientably regular maps. The second half of the article is a survey of the state-of-the-art with respect to the classification of such maps by their automorphism groups, underlying graphs, and supporting surfaces. We conclude by introducing the notion of 'external symmetries' of regular maps, going well byeyond automorphisms, and discuss the corresponding 'super-symmetric' maps.