The voltage group of a voltage graph is the group 
whose elements
are assigned as voltages to the darts of the graph. In the
derived graph cover, the vertices are pairs 
with 
a vertex of the base graph and
(Gross 1974, Gross and Tucker
1987).
Voltage Group
See also
Base Graph, Graph Cover, Group, Group Element, Voltage GraphExplore with Wolfram|Alpha
References
Gross, J. L. "Voltage Graphs." Disc. Math. 9, 239-246, 1974.Gross, J. L. and Tucker, T. W. Topological Graph Theory. New York: Wiley, 1987.Cite this as:
Weisstein, Eric W. "Voltage Group." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/VoltageGroup.html