Harries graph

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Harries graph
Harries graph.svg
The Harries graph
Named afterW. Harries
Vertices 70
Edges 105
Radius 6
Diameter 6
Girth 10
Automorphisms 120 ( S5 )
Chromatic number 2
Chromatic index 3
Book thickness 3
Queue number 2
Properties Cubic
Cage
Triangle-free
Hamiltonian
Table of graphs and parameters

In the mathematical field of graph theory, the Harries graph or Harries (3-10)-cage is a 3-regular, undirected graph with 70 vertices and 105 edges. [1]

Contents

The Harries graph has chromatic number 2, chromatic index 3, radius 6, diameter 6, girth 10 and is Hamiltonian. It is also a 3-vertex-connected and 3-edge-connected, non-planar, cubic graph. It has book thickness 3 and queue number 2. [2]

The characteristic polynomial of the Harries graph is

History

In 1972, A. T. Balaban published a (3-10)-cage graph, a cubic graph that has as few vertices as possible for girth 10. [3] It was the first (3-10)-cage discovered but it was not unique. [4]

The complete list of (3-10)-cage and the proof of minimality was given by O'Keefe and Wong in 1980. [5] There exist three distinct (3-10)-cage graphs—the Balaban 10-cage, the Harries graph and the Harries–Wong graph. [6] Moreover, the Harries–Wong graph and Harries graph are cospectral graphs.

Related Research Articles

In graph theory, the girth of an undirected graph is the length of a shortest cycle contained in the graph. If the graph does not contain any cycles, its girth is defined to be infinity. For example, a 4-cycle (square) has girth 4. A grid has girth 4 as well, and a triangular mesh has girth 3. A graph with girth four or more is triangle-free.

<span class="mw-page-title-main">Petersen graph</span> Cubic graph with 10 vertices and 15 edges

In the mathematical field of graph theory, the Petersen graph is an undirected graph with 10 vertices and 15 edges. It is a small graph that serves as a useful example and counterexample for many problems in graph theory. The Petersen graph is named after Julius Petersen, who in 1898 constructed it to be the smallest bridgeless cubic graph with no three-edge-coloring.

<span class="mw-page-title-main">Heawood graph</span> Undirected graph with 14 vertices

In the mathematical field of graph theory, the Heawood graph is an undirected graph with 14 vertices and 21 edges, named after Percy John Heawood.

<span class="mw-page-title-main">Coxeter graph</span>

In the mathematical field of graph theory, the Coxeter graph is a 3-regular graph with 28 vertices and 42 edges. It is one of the 13 known cubic distance-regular graphs. It is named after Harold Scott MacDonald Coxeter.

<span class="mw-page-title-main">Pappus graph</span>

In the mathematical field of graph theory, the Pappus graph is a bipartite 3-regular undirected graph with 18 vertices and 27 edges, formed as the Levi graph of the Pappus configuration. It is named after Pappus of Alexandria, an ancient Greek mathematician who is believed to have discovered the "hexagon theorem" describing the Pappus configuration. All the cubic distance-regular graphs are known; the Pappus graph is one of the 13 such graphs.

<span class="mw-page-title-main">Cage (graph theory)</span> Regular graph with fewest possible nodes for its girth

In the mathematical area of graph theory, a cage is a regular graph that has as few vertices as possible for its girth.

<span class="mw-page-title-main">Foster graph</span> Bipartite 3-regular graph with 90 vertices and 135 edges

In the mathematical field of graph theory, the Foster graph is a bipartite 3-regular graph with 90 vertices and 135 edges.

<span class="mw-page-title-main">Harries–Wong graph</span>

In the mathematical field of graph theory, the Harries–Wong graph is a 3-regular undirected graph with 70 vertices and 105 edges.

<span class="mw-page-title-main">Balaban 10-cage</span> Cubic graph with 70 nodes and 105 edges

In the mathematical field of graph theory, the Balaban 10-cage or Balaban (3,10)-cage is a 3-regular graph with 70 vertices and 105 edges named after Alexandru T. Balaban. Published in 1972, It was the first 10-cage discovered but it is not unique.

<span class="mw-page-title-main">McGee graph</span>

In the mathematical field of graph theory, the McGee graph or the (3-7)-cage is a 3-regular graph with 24 vertices and 36 edges.

<span class="mw-page-title-main">Balaban 11-cage</span>

In the mathematical field of graph theory, the Balaban 11-cage or Balaban (3,11)-cage is a 3-regular graph with 112 vertices and 168 edges named after Alexandru T. Balaban.

<span class="mw-page-title-main">Biggs–Smith graph</span> Cubic distance-regular graph with 102 nodes and 153 edges

In the mathematical field of graph theory, the Biggs–Smith graph is a 3-regular graph with 102 vertices and 153 edges.

<span class="mw-page-title-main">Dyck graph</span>

In the mathematical field of graph theory, the Dyck graph is a 3-regular graph with 32 vertices and 48 edges, named after Walther von Dyck.

<span class="mw-page-title-main">Nauru graph</span> 24-vertex symmetric bipartite cubic graph

In the mathematical field of graph theory, the Nauru graph is a symmetric, bipartite, cubic graph with 24 vertices and 36 edges. It was named by David Eppstein after the twelve-pointed star in the flag of Nauru.

<span class="mw-page-title-main">F26A graph</span>

In the mathematical field of graph theory, the F26A graph is a symmetric bipartite cubic graph with 26 vertices and 39 edges.

<span class="mw-page-title-main">Robertson graph</span>

In the mathematical field of graph theory, the Robertson graph or (4,5)-cage, is a 4-regular undirected graph with 19 vertices and 38 edges named after Neil Robertson.

<span class="mw-page-title-main">Horton graph</span>

In the mathematical field of graph theory, the Horton graph or Horton 96-graph is a 3-regular graph with 96 vertices and 144 edges discovered by Joseph Horton. Published by Bondy and Murty in 1976, it provides a counterexample to the Tutte conjecture that every cubic 3-connected bipartite graph is Hamiltonian.

<span class="mw-page-title-main">Ljubljana graph</span>

In the mathematical field of graph theory, the Ljubljana graph is an undirected bipartite graph with 112 vertices and 168 edges.

<span class="mw-page-title-main">Tutte 12-cage</span>

In the mathematical field of graph theory, the Tutte 12-cage or Benson graph is a 3-regular graph with 126 vertices and 189 edges named after W. T. Tutte.

<span class="mw-page-title-main">Klein graphs</span>

In the mathematical field of graph theory, the Klein graphs are two different but related regular graphs, each with 84 edges. Each can be embedded in the orientable surface of genus 3, in which they form dual graphs.

References

  1. Weisstein, Eric W. "Harries Graph". MathWorld .
  2. Jessica Wolz, Engineering Linear Layouts with SAT. Master Thesis, University of Tübingen, 2018
  3. A. T. Balaban, A trivalent graph of girth ten, J. Combin. Theory Ser. B 12, 1-5. 1972.
  4. Pisanski, T.; Boben, M.; Marušič, D.; and Orbanić, A. "The Generalized Balaban Configurations." Preprint. 2001. .
  5. M. O'Keefe and P.K. Wong, A smallest graph of girth 10 and valency 3, J. Combin. Theory Ser. B 29 (1980) 91-105.
  6. Bondy, J. A. and Murty, U. S. R. Graph Theory with Applications. New York: North Holland, p. 237, 1976.