Zeta functions of oriented line graphs of graph coverings Original Research Article

In this paper, we obtain a decomposition formula for the zeta function of an oriented line graph of a regular covering of a graph G. Furthermore, we introduce an L-function of an oriented line graph image of G, and give a decomposition formula for the zeta function of an oriented line graph of a regular covering of G by L-functions of image. As a by-product, we obtain an L-function version of Bassʹs result.