Skip to main content
Log in

Coloring, sparseness and girth

  • Published:
Israel Journal of Mathematics Aims and scope Submit manuscript

Abstract

An r-augmented tree is a rooted tree plus r edges added from each leaf to ancestors. For d, g, r ∈ N, we construct a bipartite r-augmented complete d-ary tree having girth at least g. The height of such trees must grow extremely rapidly in terms of the girth.

Using the resulting graphs, we construct sparse non-k-choosable bipartite graphs, showing that maximum average degree at most 2(k - 1) is a sharp sufficient condition for k-choosability in bipartite graphs, even when requiring large girth. We also give a new simple construction of non-k-colorable graphs and hypergraphs with any girth.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. N. Alon, Combinatorial Nullstellensatz, Combinatorics, Probability and Computing 8 (1999), 7–29.

    Article  MathSciNet  MATH  Google Scholar 

  2. N. Alon and M. Tarsi, Colorings and orientations of graphs, Combinatorica 12 (1992), 125–134.

    Article  MathSciNet  MATH  Google Scholar 

  3. P. Erdos, Graph theory and probability, Canadian Journal of Mathematics 11 (1959), 34–38.

    Article  MathSciNet  MATH  Google Scholar 

  4. P. Erdos and A. Hajnal, On chromatic number of graphs and set-systems, Acta Mathematica Academiae Scientiarum Hungaricae 17 (1966), 61–99.

    Article  MathSciNet  MATH  Google Scholar 

  5. P. Erdos, A. L. Rubin and H. Taylor, Choosability in graphs, in Proceedings of the West Coast Conference onn Combinatorics, Graph Theory and Computing (Humboldt State Univ., Arcata, CA., 1979), Congressus Numerantium, Vol. 26, Utilitas Mathematica, Winnipeg, MB, 1980, pp. 125–157.

    MathSciNet  Google Scholar 

  6. Z. Füredi, A. Kostochka and M. Kumbhat, Choosability with separation of complete multipartite graphs and hypergraphs, Journal of Graph Theory 76 (2014), 129–137.

    Article  MathSciNet  MATH  Google Scholar 

  7. S. L. Hakimi, On the degrees of the vertices of a directed graph, Journal of the Franklin Institute 279 (1965), 290–308.

    Article  MathSciNet  MATH  Google Scholar 

  8. A. V. Kostochka and J. Nesetril, Properties of Descartes’ construction of trianglefree graphs with high chromatic number, Combinatorics, Probability and Computing 8 (1999), 467–472.

    Article  MathSciNet  MATH  Google Scholar 

  9. A. V. Kostochka and M. Stiebitz, On the number of edges in colour-critical graphs and hypergraphs, Combinatorica 20 (2000), 521–530.

    Article  MathSciNet  MATH  Google Scholar 

  10. J. Kratochvíl, Zs. Tuza and M. Voigt, Brooks-type theorems for choosability with separation, Journal of Graph Theory 27 (1998), 43–39.

    Article  MathSciNet  MATH  Google Scholar 

  11. I. Kriz, A hypergraph free construction of highly chromatic graphs without short cycles, Combinatorica 9 (1989), 227–229.

    MathSciNet  Google Scholar 

  12. L. Lovász, On chromatic number of finite set-systems, Acta Mathematica Academiae Scientiarum Hungaricae 19 (1968), 59–67.

    Article  MathSciNet  MATH  Google Scholar 

  13. J. Nesetril and V. Rödl, Chromatically optimal rigid graphs, Journal of Combinatorial Theory. B 46 (1989), 133–141.

    Article  MathSciNet  MATH  Google Scholar 

  14. M. Richardson, Solutions of irreflexive relations, Annals of Mathematics 58 (1953), 573–580.

    Article  MathSciNet  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Noga Alon.

Additional information

Research supported in part by a USA-Israeli BSF grant, by an ISF grant, by the Israeli I-Core program and by the Oswald Veblen Fund.

Research supported in part by NSF grant DMS-1266016.

Research supported by Recruitment Program of Foreign Experts, 1000 Talent Plan, State Administration of Foreign Experts Affairs, China.

Research supported by CNSF 11571319.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Alon, N., Kostochka, A., Reiniger, B. et al. Coloring, sparseness and girth. Isr. J. Math. 214, 315–331 (2016). https://doi.org/10.1007/s11856-016-1361-2

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11856-016-1361-2

Navigation