The Knödel graph is a regular bipartite graph of vertex degree on nodes for even and with edges defined as follows. Label the vertices with and . Then there is an edge between and for every where , ..., (Fertin and Raspaud 2004, Clancy et al. 2019).
This class of graphs was introduced by Knödel (1975) in constructing a time-optimal algorithm for gossiping among vertices with even , but were only formally defined by Fraigniaud and Peters (2001) (Fertin and Raspaud 2004).
Knödel graphs are Cayley and vertex-transitive graphs (Fertin and Raspaud 2004). They are also Haar graphs.
Special cases are summarized in the following table.
graph | |
path graph | |
ladder rung graph | |
square graph | |
cycle graph | |
Möbius ladder | |
Franklin graph | |
Heawood graph | |
Möbius-Kantor graph | |
-honeycomb toroidal graph | |
circulant graph | |
Haar graph |
The edge connectivity of is given by
(1)
|
and the vertex connectivity satisfies
(2)
|
(Fertin and Raspaud 2004).
Zheng et al. (2008) showed that the graph crossing numbers of the cubic Knödel graph is given by
(3)
| |||
(4)
| |||
(5)
|
for even (Clancy et al. 2019).