Semi-symmetric graph
From Wikipedia, the free encyclopedia
In mathematics, an semi-symmetric graph is a graph that is edge-transitive and regular, but not vertex-transitive.
In other words, a regular graph is semi-symmetric if its automorphism group acts transitively upon its edges but not upon its vertices.
[edit] Examples and properties
- Dragan Marušič and Aleksander Malnic have shown that the smallest cubic semi-symmetric graph is the Gray graph on 54 vertices.
- Any semi-symmetric graph is bipartite.
