Isomorphic tetravalent cyclic Haar graphs

Abstract

Let S be a subset of the cyclic group Zn. The cyclic Haar graph iJ(Zn,S) is the bipartite graph with color classes Zn+ and Zn-, and edges {x+, y -}, where x, y j Zn and y - x j S. In this paper we give sufficient and necessary conditions for the isomorphism of two connected cyclic Haar graphs of valency 4. © 2014 DMFA Slovenije.