Path graph

This article is about a family of graphs. For paths as parts of arbitrary graphs, see Path (graph theory).

Not to be confused with line graph.

Path graph
250px A path graph on 6 vertices
Vertices	n
Edges	n - 1
Radius	⌊n/2⌋
Diameter	n - 1
Automorphisms	2
Chromatic number	2
Chromatic index	2
Spectrum	{2 cos(k π / (n + 1))1; k=1,...,n}
Properties	Unit distance Bipartite graph Tree
Notation	$P_n$

In the mathematical field of graph theory, a path graph or linear graph is a particularly simple example of a tree, namely a tree with two or more vertices that is not branched at all, that is, contains only vertices of degree 2 and 1. In particular, it has two terminal vertices (vertices that have degree 1), while all others (if any) have degree 2.

Paths and cycles are fundamental concepts of graph theory, described in the introductory sections of most graph theory texts. See e.g. Bondy and Murty (1976), Gibbons (1985), or Diestel (2005).

See also

• Glossary of graph theory
• Path (graph theory)
• Caterpillar tree
• Complete graph
• Null graph
• Path decomposition

External links

• Weisstein, Eric W., "Path Graph", MathWorld.cs:Cesta (graf)