Operations on Oriented Maps

• Main Authors: Tomaž Pisanski, Gordon Williams, Leah Wrenn Berman
• Format: Article
• Language: English
• Published: MDPI AG 2017-11-01
• Series: Symmetry
• Subjects: map; oriented map; truncation; dual; medial; snub; flag graph; arc graph
• Online Access: https://www.mdpi.com/2073-8994/9/11/274

A map on a closed surface is a two-cell embedding of a finite connected graph. Maps on surfaces are conveniently described by certain trivalent graphs, known as flag graphs. Flag graphs themselves may be considered as maps embedded in the same surface as the original graph. The flag graph is the underlying graph of the dual of the barycentric subdivision of the original map. Certain operations on maps can be defined by appropriate operations on flag graphs. Orientable surfaces may be given consistent orientations, and oriented maps can be described by a generating pair consisting of a permutation and an involution on the set of arcs (or darts) defining a partially directed arc graph. In this paper we describe how certain operations on maps can be described directly on oriented maps via arc graphs.