Abstract
We define an -variable Bartholdi zeta function and an
-variable Bartholdi
-function of a graph
, and give determinant expressions of them. We present a decomposition formula for the
-variable Bartholdi zeta function of a regular covering of
. Furthermore, we express the
-variable Bartholdi zeta function of a regular covering of G as a product of its
-variable Bartholdi L-functions.
Keywords:
Acknowledgements
We would like to thank the referee for many valuable comments and many helpful suggestions.
Notes
No potential conflict of interest was reported by the author(s).