## Isomorphism classes of graph bundles.(English)Zbl 0739.05042

Summary: Recently, M. Hofmeister [J. Graph Theory 12, No. 3, 437-444 (1988; Zbl 0649.05036)] counted all nonisomorphic double coverings of a graph by using its $$\mathbb{Z}_ 2$$ cohomology groups, and J. Kwak and J. Lee did the same work for some finite-fold coverings. We give an algebraic characterization of isomorphic graph bundles, from which we get a formula to count all nonisomorphic graphbundles. Some applications to wheels are also discussed.

### MSC:

 05C30 Enumeration in graph theory

### Keywords:

isomorphism classes; graph bundles

Zbl 0649.05036
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