Konno–Sato theorem for a covering of a graph
摘要
The Grover matrix of a graph G is a typical time evolution matrix of a discrete-time quantum walk on G. We treat the Grover matrix of a finite covering of G and present a decomposition formula for the determinant of it. Furthermore, we define an L-function of a graph with respect to the Grover matrix and present its determinant expression. As a corollary, we express the determinant of the Grover matrix of a covering of G as a product of its L-functions.