Israel Journal of Mathematics

, Volume 170, Issue 1, pp 125–134 | Cite as

A short proof of w 1 n (Hom(C 2r+1, K n+2)) = 0 for all n and A graph colouring theorem by Babson and Kozlov

  • Carsten Schultz


We show that the n-th power of the first Stiefel-Whitney class of the ℤ2-action on the graph complex Hom(C 2r+1, K n+2) is zero, confirming a conjecture by Babson and Kozlov. This yields a considerably simplified proof of their graph colouring theorem, which is also known as the Lovsz conjecture.


Chromatic Number Graph Colouring Order Complex Cubical Complex Graph Complex 
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Copyright information

© Hebrew University Magnes Press 2009

Authors and Affiliations

  1. 1.Institut für Mathematik, MA 6-2Technische Universität BerlinBerlinGermany

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