Barnette–Bosák–Lederberg graph

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Short description: Non-Hamiltonian simple polyhedron
Barnette–Bosák–Lederberg graph
Barnette-Bosak-Lederberg graph (Lombardi drawing).svg
Vertices38
Edges57
Radius5
Diameter9
Girth4
Chromatic number3
Chromatic index3
PropertiesCubic
Planar
Polyhedral
Table of graphs and parameters

In the mathematical field of graph theory, the Barnette–Bosák–Lederberg graph is a cubic (that is, 3-regular) polyhedral graph with no Hamiltonian cycle, the smallest such graph possible.[1] It was discovered in the mid-1960s by Joshua Lederberg, David Barnette, and Juraj Bosák, after whom it is named. It has 38 vertices and 57 edges.[2][3][4]

Other larger non-Hamiltonian cubic polyhedral graphs include the 46-vertex Tutte graph and a 44-vertex graph found by Emanuels Grīnbergs using Grinberg's theorem. The Barnette–Bosák–Lederberg graph has a similar construction to the Tutte graph but is composed of two Tutte fragments, connected through a pentagonal prism, instead of three connected through a tetrahedron. Without the constraint of having exactly three edges at every vertex, much smaller non-Hamiltonian polyhedral graphs are possible, including the Goldner–Harary graph and the Herschel graph.

References

  1. Holton, D. A.; McKay, B. D. (1988), "The smallest non-Hamiltonian 3-connected cubic planar graphs have 38 vertices", Journal of Combinatorial Theory, Series B 45 (3): 305–319, doi:10.1016/0095-8956(88)90075-5 
  2. "Hamilton circuits of convex trivalent polyhedra (up to 18 vertices)", The American Mathematical Monthly 74 (5): 522–527, 1967, doi:10.2307/2314879 
  3. Bosák, J. (1967), "Hamiltonian lines in cubic graphs", Theory of Graphs (Internat. Sympos., Rome, 1966), New York: Gordon and Breach, pp. 35–46 
  4. Weisstein, Eric W.. "Barnette-Bosák-Lederberg Graph". http://mathworld.wolfram.com/Barnette-Bosak-LederbergGraph.html.