Skip to main content

Hadwiger’s Conjecture

  • Chapter
  • First Online:
Book cover Open Problems in Mathematics

Abstract

This is a survey of Hadwiger’s conjecture from 1943, that for all t ≥ 0, every graph either can be t-coloured, or has a subgraph that can be contracted to the complete graph on t + 1 vertices. This is a tremendous strengthening of the four-colour theorem, and is probably the most famous open problem in graph theory.

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

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 149.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 199.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 199.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  1. F. N. Abu-Khzam and M. A. Langston, “Graph coloring and the immersion order”, Computing and Combinatorics, Lecture Notes in Comput. Sci. 2697 (2003) (Springer, Berlin) 394–403.

    Google Scholar 

  2. B. Albar and D. Gonçalves, “On triangles in K r -minor free graphs”, submitted for publication (manuscript April 2013), http://arXiv.org/abs/1304.5468.

  3. N. Alon, G. Ding, B. Oporowski, and D. Vertigan, “Partitioning into graphs with only small components”, J. Combinatorial Theory, Ser. B, 87 (2003), 231–243.

    Article  MathSciNet  MATH  Google Scholar 

  4. K. Appel and A. Haken, “Every planar map is four colorable. Part I. Discharging”, Illinois J. Math. 21 (1977), 429–490.

    MathSciNet  MATH  Google Scholar 

  5. K. Appel, A. Haken and J. Koch, “Every planar map is four colorable. Part II. Reducibility”, Illinois J. Math. 21 (1977), 491–567.

    MathSciNet  MATH  Google Scholar 

  6. J. Balogh and A. V. Kostochka, “Large minors in graphs with given independence number”, Discrete Math. 311 (2011), 2203–2215.

    Article  MathSciNet  MATH  Google Scholar 

  7. J. Barát, G. Joret and D. R. Wood, “Disproof of the list Hadwiger conjecture”, Electronic Journal of Combinatorics 18 (2011), p232.

    MathSciNet  MATH  Google Scholar 

  8. T. Böhme, K. Kawarabayashi, J. Maharry and B. Mohar, “Linear connectivity forces large complete bipartite graph minors”, J. Combinatorial Theory, Ser. B, 99 (2009), 557–582.

    Article  MATH  Google Scholar 

  9. T. Böhme, A. Kostochka and A. Thomason, “Minors in graphs with high chromatic number”, Combin. Probab. Comput. 20 (2011), 513–518.

    Article  MathSciNet  MATH  Google Scholar 

  10. B. Bollobás, P. A. Catlin and P. Erdős, “Hadwiger’s conjecture is true for almost every graph”, Europ. J. Combinatorics 1 (1980), 195–199.

    Article  MATH  Google Scholar 

  11. M. Borowiecki, “Research problem 172”, Discrete Mathematics 121 (1993), 235–236.

    Article  MathSciNet  Google Scholar 

  12. P. Catlin, “Hajós’ graph-coloring conjecture: Variations and counterexamples,” J. Combinatorial Theory, Ser. B, 26 (1979), 268–274.

    Article  MathSciNet  MATH  Google Scholar 

  13. M. Chudnovsky and A. Fradkin, “An approximate version of Hadwiger’s conjecture for claw-free graphs”, J. Graph Theory 63 (2010), 259–278.

    MathSciNet  MATH  Google Scholar 

  14. M. Chudnovsky, B. Reed and P. Seymour, “The edge-density for K 2, t minors”, J. Combinatorial Theory, Ser. B, 101 (2011), 18–46.

    Article  MathSciNet  MATH  Google Scholar 

  15. M. Chudnovsky and P. Seymour, “Packing seagulls”, Combinatorica, 32 (2012), 251–282.

    Article  MathSciNet  MATH  Google Scholar 

  16. M. Devos, G. Ding, B. Oporowski, B. Reed, D. Sanders, P. Seymour and D. Vertigan, “Excluding any graph as a minor allows a low tree-width 2-coloring”, J. Combinatorial Theory, Ser. B, 91 (2004), 25–41.

    Article  MathSciNet  MATH  Google Scholar 

  17. M. DeVos, Z. Dvořék, J. Fox, J. McDonald, B. Mohar and D. Scheide, “A minimum degree condition forcing complete graph immersion”, Combinatorica 34 (2014), 279–298.

    Article  MathSciNet  MATH  Google Scholar 

  18. M. DeVos, K. Kawarabayashi, B. Mohar and H. Okamura, “Immersing small complete graphs”, Ars Mathematica Contemporanea 3 (2010), 139–146.

    MathSciNet  MATH  Google Scholar 

  19. G. Ding and S. Dziobiak, “Vertex-bipartition method for colouring minor-closed classes of graphs”, Combinatorics, Probability and Computing 19 (2010), 579–591.

    Article  MathSciNet  MATH  Google Scholar 

  20. G. Ding, T. Johnson and P. Seymour, “Spanning trees with many leaves”, J. Graph Theory, 37 (2001), 189–197.

    Article  MathSciNet  MATH  Google Scholar 

  21. G. Ding, B. Oporowski, D. Sanders, and D. Vertigan, “Surfaces, tree-width, clique-minors, and partitions”, J. Combinatorial Theory, Ser. B, 79 (2000), 221–246.

    Article  MathSciNet  MATH  Google Scholar 

  22. G. A. Dirac, “A property of 4-chromatic graphs and some remarks on critical graphs”, J. London Math. Soc. 27 (1952), 85–92.

    Article  MathSciNet  MATH  Google Scholar 

  23. P. Duchet and H. Meyniel, “On Hadwiger’s number and the stability number”, in Graph Theory (Proc. conf. on graph theory, Cambridge, 1981; B. Bollobás, ed.), Annals of Discrete Math. 13, North-Holland, Amsterdam, New York, 71–73; North-Holland Mathematical Studies 62 (1982), 71–73.

    Google Scholar 

  24. R.J. Duffin, “Topology of series–parallel networks”, J. Math. Analys. Appl. 10 (1965), 303–318.

    Article  MathSciNet  MATH  Google Scholar 

  25. Zdeněk Dvořák and Liana Yepremyan, “Complete graph immersions and minimum degree”, http://arxiv.org/abs/1512.00513.

  26. K. Edwards, D. Y. Kang, J. Kim, S. Oum and P. Seymour, “A relative of Hadwiger’s conjecture”, SIAM J. Discrete Math. 29 (2015), 2385–2388.

    Article  MathSciNet  MATH  Google Scholar 

  27. P. Erdős and S. Fajtlowicz, “On the conjecture of Hajós”, Combinatorica 1 (1981), 141–143.

    Article  MathSciNet  MATH  Google Scholar 

  28. W. Fernandez de la Vega, “On the maximum density of graphs which have no subcontraction to K s ”, Discrete Math. 46 (1983), 109–110.

    Article  MathSciNet  MATH  Google Scholar 

  29. J. Fox, “Complete minors and independence number”, SIAM J. Discrete Math. 24 (2010), 1313–1321.

    Article  MathSciNet  MATH  Google Scholar 

  30. J. Fox, C. Lee and B. Sudakov, “Chromatic number, clique subdivisions, and the conjectures of Hajós and Erdős-Fajtlowicz”, Combinatorica 33 (2013), 181–197.

    Article  MathSciNet  MATH  Google Scholar 

  31. A. Fradkin, “Clique minors in claw-free graphs”, J. Combinatorial Theory, Ser. B, 102 (2012), 71–85.

    Article  MathSciNet  MATH  Google Scholar 

  32. J. Geelen, A. Gerards, B. Reed, P. Seymour and A. Vetta, “On the odd-minor variant of Hadwiger’s conjecture”, J. Combinatorial Theory, Ser B, 99 (2009), 20–29.

    Article  MathSciNet  MATH  Google Scholar 

  33. A. M. H. Gerards, Graphs and polyhedra. Binary spaces and cutting planes, volume 73 of CWI Tract. Stichting Mathematisch Centrum voor Wiskunde en Informatica, Amsterdam, 1990; http://oai.cwi.nl/oai/asset/12714/12714A.pdf.

  34. D. Gonçalves, “On vertex partitions and some minor-monotone graph parameters”, J. Graph Theory 66 (2011), 49–56.

    Google Scholar 

  35. G. R. Grimmitt and C. J. H. McDiarmid, “On colouring random graphs”, Math. Proc. Cambridge Phil. Soc. 77 (1975), 313–324.

    Article  MathSciNet  MATH  Google Scholar 

  36. B. Guenin, “Graphs without odd-K5 minors are 4-colourable”, in preparation.

    Google Scholar 

  37. H. Hadwiger, “Über eine Klassifikation der Streckenkomplexe”, Vierteljschr. Naturforsch. Ges. Zürich 88 (1943), 133–143.

    MathSciNet  MATH  Google Scholar 

  38. T. Jensen and B. Toft, Graph Coloring Problems, Wiley, Chichester UK, 1995, page 115.

    MATH  Google Scholar 

  39. L. Jørgensen, “Contractions to K 8”, J. Graph Theory 18 (1994), 431–448.

    Article  MathSciNet  MATH  Google Scholar 

  40. K. Kawarabayashi, “A weakening of the odd Hadwiger’s conjecture”, Combinatorics, Probability and Computing 17 (2008), 815–821.

    Article  MathSciNet  MATH  Google Scholar 

  41. K. Kawarabayashi, “Note on coloring graphs without odd-K k -minors”, J. Combinatorial Theory, Ser. B, 99 (2009), 728–731.

    Article  MathSciNet  MATH  Google Scholar 

  42. K. Kawarabayashi, “On the connectivity of minimum and minimal counterexamples to Hadwiger’s conjecture”, J. Combinatorial Theory, Ser. B, 97 (2007), 144–150.

    Article  MathSciNet  MATH  Google Scholar 

  43. K. Kawarabayashi and B. Mohar, “A relaxed Hadwiger’s conjecture for list colorings”, J. Combinatorial Theory Ser. B, 97 (2007), 647–651.

    Article  MathSciNet  MATH  Google Scholar 

  44. K. Kawarabayashi, S. Norin, R. Thomas and P. Wollan, “K 6 minors in large 6-connected graphs”, in preparation; http://arXiv.org/abs/1203.2192.

  45. K. Kawarabayashi and B. Reed, “Fractional coloring and the odd Hadwiger’s conjecture”, European J. Comb. 29 (2008), 411–417.

    Article  MathSciNet  MATH  Google Scholar 

  46. K. Kawarabayashi and B. Reed, “Hadwiger’s conjecture is decidable”, Proc. 41st Annual ACM Symposium on Theory of Computing, STOC 2009, 445–454.

    Google Scholar 

  47. K. Kawarabayashi and Z. Song, “Some remarks on the odd Hadwiger’s conjecture”, Combinatorica, 27 (2007), 429–438.

    Article  MathSciNet  MATH  Google Scholar 

  48. A. V. Kostochka, “K s, t minors in (s + t)-chromatic graphs, II”, J. Graph Theory 75 (2014), 377–386.

    Google Scholar 

  49. A. V. Kostochka, “Lower bound on the Hadwiger number of graphs by their average degree”, Combinatorica 4 (1984), 307–316.

    Article  MathSciNet  MATH  Google Scholar 

  50. A. V. Kostochka, “On K s, t minors in (s + t)-chromatic graphs”, J. Graph Theory 65 (2010), 343–350.

    Google Scholar 

  51. A. V. Kostochka, “The minimum Hadwiger number for graphs with a given mean degree of vertices”, Metody Diskret. Analiz. 38 (1982), 37–58; AMS Translations (2), 132 (1986), 15–32.

    Google Scholar 

  52. A. V. Kostochka and N. Prince, “Dense graphs have K 3, t minors”, Discrete Math. 310 (2010), 2637–2654.

    Article  MathSciNet  MATH  Google Scholar 

  53. A. V. Kostochka and N. Prince, “On K s, t minors in graphs of given average degree”, Discrete Math. 308 (2008), 4435–4445.

    Google Scholar 

  54. A. V. Kostochka and N. Prince, “On K s, t -minors in graphs with given average degree, II”, Discrete Math. 312 (2012), 3517–3522.

    Google Scholar 

  55. D. Kühn and D. Osthus, “Forcing complete unbalanced bipartite minors”, Europ. J. Combinatorics 26 (2005), 75–81.

    Article  MATH  Google Scholar 

  56. K. Kuratowski, “Sur le problème des courbes gauches en topologie”, Fund. Math. 15 (1930), 271–283.

    MATH  Google Scholar 

  57. F. Lescure and H. Meyniel, “On a problem upon configurations contained in graphs with given chromatic number”, Graph Theory in Memory of G. A. Dirac (Sandbjerg, 1985), Ann. Discrete Math. 41, North-Holland, Amsterdam, 1989, 325–331.

    Google Scholar 

  58. C. Liu and S. Oum, “Partitioning H-minor free graphs into three subgraphs with no large components”, manuscript March 2015; http://arXiv.org/abs/1503.08371v1.

  59. W. Mader, “Homomorphieeigenschaften und mittlere Kantendichte von Graphen” Math. Ann. 174 (1967), 265–268.

    Article  MathSciNet  MATH  Google Scholar 

  60. W. Mader, “Homomorphiesätze für Graphen”, Math. Ann., 178 (1968), 154–168.

    Article  MathSciNet  MATH  Google Scholar 

  61. W. Mader, “Über trennende Eckenmengen in homomorphiekritischen Graphen”, Math. Ann. 175 (1968), 245–252.

    MathSciNet  MATH  Google Scholar 

  62. J.S. Myers, “The extremal function for unbalanced bipartite minors”, Discrete Math. 271 (2003), 209–222.

    Article  MathSciNet  MATH  Google Scholar 

  63. J. S. Myers and A. Thomason, “The extremal function for noncomplete minors”, Combinatorica 25 (2005), 725–753.

    Article  MathSciNet  MATH  Google Scholar 

  64. S. Norin, “Conquering graphs of bounded treewidth”, unpublished manuscript, April 2015.

    Google Scholar 

  65. B. Reed and P. Seymour, “Fractional colouring and Hadwiger’s conjecture”, J. Combinatorial Theory, Ser. B, 74 (1998), 147–152.

    Article  MathSciNet  MATH  Google Scholar 

  66. B. Reed and P. Seymour, “Hadwiger’s conjecture for line graphs”, European J. Math., 25 (2004), 873–876.

    MathSciNet  MATH  Google Scholar 

  67. B. Reed and D. Wood, “Forcing a sparse minor”, Combinatorics, Probability and Computing, 25 (2016), 300–322.

    Article  MathSciNet  Google Scholar 

  68. N. Robertson and P. Seymour, “Graph minors. XVI. Excluding a non-planar graph”, J. Combinatorial Theory, Ser. B, 89 (2003), 43–76.

    Article  MathSciNet  MATH  Google Scholar 

  69. N. Robertson, P. Seymour and R. Thomas, “Excluding infinite clique minors”, Memoirs Amer. Math. Soc., no. 566, vol. 118 (1995).

    Google Scholar 

  70. N. Robertson, P. Seymour and R. Thomas, “Excluding subdivisions of infinite cliques”, Trans. Amer. Math. Soc. 332 (1992), 211–223.

    Article  MathSciNet  MATH  Google Scholar 

  71. N. Robertson, P. Seymour and R. Thomas, “Hadwiger’s conjecture for K 6-free graphs”, Combinatorica 13 (1993), 279–361.

    Article  MathSciNet  MATH  Google Scholar 

  72. Z. Song and R. Thomas, “The extremal function for K 9 minors”, J. Combinatorial Theory, Ser. B, 96 (2006), 240–252.

    Article  MathSciNet  MATH  Google Scholar 

  73. A. Thomason, “An extremal function for contractions of graphs”, Math. Proc. Camb. Phil. Soc. 95 (1984), 261–265.

    Article  MathSciNet  MATH  Google Scholar 

  74. A. Thomason, “The extremal function for complete minors”, J. Combinatorial Theory Ser. B, 81 (2001), 318–338.

    Article  MathSciNet  MATH  Google Scholar 

  75. C. Thomassen, “Every planar graph is 5-choosable”, J. Combinatorial Theory, Ser. B, 62 (1994), 180–181.

    Article  MathSciNet  MATH  Google Scholar 

  76. C. Thomassen, “Totally odd K 4-subdivisions in 4-chromatic graphs”, Combinatorica 21 (2001), 417–443.

    Article  MathSciNet  MATH  Google Scholar 

  77. B. Toft, “Problem 10,” in Recent Advances in Graph Theory, Proc. Symp. Prague June 1974, M. Fiedler (Ed.), Academia Praha, 1975, 543–544.

    Google Scholar 

  78. B. Toft, A Survey of Hadwiger’s Conjecture, in: Surveys in Graph Theory (edited by G. Chartrand and M. Jacobson), Congr. Numer. 115 (1996), 249–283.

    Google Scholar 

  79. W. T. Tutte, “On the algebraic theory of graph colorings”, J. Combinatorial Theory, 1 (1966), 15–50.

    Article  MathSciNet  MATH  Google Scholar 

  80. D. van der Zypen, “A weak form of Hadwiger’s conjecture” SOP Trans. Appl. Math. 1 (2014), 84–87.

    Article  Google Scholar 

  81. M. Voigt, “List colourings of planar graphs”, Discrete Mathematics 120 (1993), 215–219.

    Article  MathSciNet  MATH  Google Scholar 

  82. K. Wagner, “Beweis einer Abschwächung der Hadwiger-Vermutung”, Math. Ann. 153 (1964), 139–141.

    Article  MathSciNet  MATH  Google Scholar 

  83. K. Wagner, “Über eine Eigenschaft der ebenen Komplexe”, Math. Ann. 114 (1937), 570–590.

    Article  MathSciNet  MATH  Google Scholar 

  84. D. R. Wood, “Contractibility and the Hadwiger conjecture”, Europ. J. Combinatorics., 31 (2010), 2102–2109.

    Article  MathSciNet  MATH  Google Scholar 

  85. D. R. Wood, “On tree-partition-width”, European J. Combinatorics 30 (2009), 1245–1253.

    Article  MathSciNet  MATH  Google Scholar 

  86. W. Zang, “Proof of Toft’s conjecture: every graph containing no fully odd K 4 is 3-colorable”, J. Combinatorial Optimization 2 (1998), 117–199.

    Article  MathSciNet  MATH  Google Scholar 

Download references

Acknowledgements

Thanks to several people who made suggestions for improvement, particularly Jacob Fox, Ken-ichi Kawarabayashi, Sasha Kostochka, Bojan Mohar, Sergey Norin, Sophie Spirkl, Robin Thomas, Bjarne Toft, Paul Wollan and David Wood. Supported by ONR grant N00014-10-1-0680 and NSF grant DMS-1265563.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Paul Seymour .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2016 Springer International Publishing Switzerland

About this chapter

Cite this chapter

Seymour, P. (2016). Hadwiger’s Conjecture. In: Nash, Jr., J., Rassias, M. (eds) Open Problems in Mathematics. Springer, Cham. https://doi.org/10.1007/978-3-319-32162-2_13

Download citation

Publish with us

Policies and ethics