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Diamond graph

Diamond graph
Diamond graph.svg
Vertices 4
Edges 5
Radius 1
Diameter 2
Girth 3
Automorphisms 4 (Z/2Z×Z/2Z)
Chromatic number 3
Chromatic index 3
Properties Hamiltonian
Planar
Unit distance

In the mathematical field of graph theory, the diamond graph is a planar undirected graph with 4 vertices and 5 edges. It consists of a complete graph minus one edge.

The diamond graph has radius 1, diameter 2, girth 3, chromatic number 3 and chromatic index 3. It is also a 2-vertex-connected and a 2-edge-connected gracefulHamiltonian graph.

A graph is diamond-free if it has no diamond as an induced subgraph. The triangle-free graphs are diamond-free graphs, since every diamond contains a triangle. The diamond-free graphs are locally clustered: that is, they are the graphs in which every neighborhood is a cluster graph.

The family of graphs in which each connected component is a cactus graph is downwardly closed under graph minor operations. This graph family may be characterized by a single forbidden minor. This minor is the diamond graph.


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Wikipedia

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