Graph Projection
In graph covering theory, a graph projection is the map p:G^~->G from a covering graph to its base graph. It sends vertices and edges of G^~ to their images in G and, for a graph cover, maps the edges incident to each lifted vertex bijectively onto the edges incident to its image in the base graph (Gross and Tucker 1977, Gross and Tucker 1987).
See also
Base Graph, Graph Cover, Lift, Voltage GraphExplore with Wolfram|Alpha
WolframAlpha
More things to try:
References
Gross, J. L. and Tucker, T. W. "Generating All Graph Coverings by Permutation Voltage Assignments." Disc. Math. 18, 273-283, 1977.Gross, J. L. and Tucker, T. W. Topological Graph Theory. New York: Wiley, 1987.Cite this as:
Weisstein, Eric W. "Graph Projection." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/GraphProjection.html