
In
graph theory, a line perfect graph is a
graph whose
line graph is a
perfect graph. Equivalently, these are the graphs in which every odd-length
simple cycle is a triangle.
A graph is line perfect if and only if each of its
biconnected components is a
bipartite graph
In the mathematical field of graph theory, a bipartite graph (or bigraph) is a graph whose vertices can be divided into two disjoint and independent sets U and V, that is every edge connects a vertex in U to one in V. Vertex sets U and V are ...
, the
complete graph , or a
triangular book . Because these three types of biconnected component are all perfect graphs themselves, every line perfect graph is itself perfect. By similar reasoning, every line perfect graph is a
parity graph, a
Meyniel graph, and a
perfectly orderable graph.
Line perfect graphs generalize the bipartite graphs, and share with them the properties that the
maximum matching and
minimum vertex cover
In graph theory, a vertex cover (sometimes node cover) of a graph is a set of vertices that includes at least one endpoint of every edge of the graph.
In computer science, the problem of finding a minimum vertex cover is a classical optimizat ...
have the same size, and that the
chromatic index equals the
maximum degree
This is a glossary of graph theory. Graph theory is the study of graphs, systems of nodes or vertices connected in pairs by lines or edges.
Symbols
A
B
...
.
See also
*
Strangulated graph, a graph in which every
peripheral cycle
In graph theory, a peripheral cycle (or peripheral circuit) in an undirected graph is, intuitively, a cycle that does not separate any part of the graph from any other part. Peripheral cycles (or, as they were initially called, peripheral polygo ...
is a triangle
References
{{reflist, refs=
[{{citation
, last = de Werra , first = D.
, doi = 10.1007/BF01609025
, issue = 2
, journal = Mathematical Programming
, mr = 509968
, pages = 236–238
, title = On line-perfect graphs
, volume = 15
, year = 1978.]
[{{citation
, last1 = Grötschel , first1 = Martin , author1-link = Martin Grötschel
, last2 = Lovász , first2 = László , author2-link = László Lovász
, last3 = Schrijver , first3 = Alexander , author3-link = Alexander Schrijver
, doi = 10.1007/978-3-642-78240-4
, edition = 2nd
, isbn = 3-540-56740-2
, mr = 1261419
, page = 281
, publisher = Springer-Verlag, Berlin
, series = Algorithms and Combinatorics
, title = Geometric algorithms and combinatorial optimization
, url = https://books.google.com/books?id=hWvmCAAAQBAJ&pg=PA281
, volume = 2
, year = 1993.]
[{{citation
, last = Maffray , first = Frédéric
, doi = 10.1016/0095-8956(92)90028-V
, issue = 1
, journal = ]Journal of Combinatorial Theory
The ''Journal of Combinatorial Theory'', Series A and Series B, are mathematical journals specializing in combinatorics and related areas. They are published by Elsevier. ''Series A'' is concerned primarily with structures, designs, and applicat ...
, mr = 1159851
, pages = 1–8
, series = Series B
, title = Kernels in perfect line-graphs
, volume = 55
, year = 1992, doi-access = free
.
[{{citation
, last = Trotter , first = L. E., Jr.
, doi = 10.1007/BF01593791
, issue = 2
, journal = Mathematical Programming
, mr = 0457293
, pages = 255–259
, title = Line perfect graphs
, volume = 12
, year = 1977]
[{{citation
, last = Wagler , first = Annegret
, contribution = Critical and anticritical edges in perfect graphs
, doi = 10.1007/3-540-45477-2_29
, mr = 1905643
, pages = 317–327
, publisher = Springer , location = Berlin
, series = Lecture Notes in Computer Science
, title = Graph-Theoretic Concepts in Computer Science: 27th International Workshop, WG 2001, Boltenhagen, Germany, June 14–16, 2001, Proceedings
, volume = 2204
, year = 2001.]
Perfect graphs