The edge-density of 4-critical planar graphs

Combinatorica volume 8, pages137–139(1988)Cite this article

Abstract

Improving a recent result of G. Koester, it is shown that there exist 4-critical planar graphs in which the number of edges is more than twice the number of vertices.

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References

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    T. Gallai, Critical graphs.Theory of Graphs and its Applications (Proc. Symp. Smolenice 1963), Publ. House Czechoslovak Acad. Sci..Prague 1964, 43–45.

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    G. Koester, Bemerkung zu einem Problem von H. Grötzsch.Wiss. Z. Univ. Halle,33 (1984), 129.

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    G. Koester, Note to a problem of T. Gallai and G. A. Dirac,Combinatorica.5 (1985), 227–228.

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Affiliations

  1. University of Washington GN-50, 98195, Seattle, WA, USA

    B. Grünbaum

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  1. B. Grünbaum
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Grünbaum, B. The edge-density of 4-critical planar graphs. Combinatorica 8, 137–139 (1988). https://doi.org/10.1007/BF02122562

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AMS subject classification (1980)

  • 05 C1 5