Affiliation:
1. Department of Science and Mathematics , IIIT Guwahati , Guhawati , India
Abstract
Abstract
The automorphism group of a map on a surface acts naturally on its flags (triples of incident vertices, edges, and faces). We will study the action of the automorphism group of a map on its edges. A map is semi-equivelar if all of its vertices have the same type of face-cycles. A semi-equivelar toroidal map refers to a semi-equivelar map embedded on a torus. If a map has k edge orbits under its automorphism group, it is referred to as a k-edge orbital or k-orbital. Specifically, it is referred to as an edge-transitive map if
k
=
1
{k=1}
. If any two edges have the same edge-symbol, a map is said to be edge-homogeneous. Every edge-homogeneous toroidal map has an edge-transitive cover, as proved in [A. Orbanić, D. Pellicer, T. Pisanski and T. W. Tucker,
Edge-transitive maps of low genus,
Ars Math. Contemp. 4 2011, 2, 385–402]. In this article, we show the existence and give a classification of k-edge covers of semi-equivelar toroidal maps.