Skip to main content
Log in

The universality of Hom complexes of graphs

  • Published:
Combinatorica Aims and scope Submit manuscript

Abstract

It is shown that given a connected graph T with at least one edge and an arbitrary finite simplicial complex X, there is a graph G such that the complex Hom(T,G) is homotopy equivalent to X. The proof is constructive, and uses a nerve lemma. Along the way several results regarding Hom complexes, exponentials of graphs, and subdivisions are established that may be of independent interest.

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. Anders Björner: Topological methods, in: Handbook of combinatorics, Vol. 1, 2, pages 1819–1872, Elsevier, Amsterdam, 1995.

    Google Scholar 

  2. Eric Babson and Dmitry N. Kozlov: Complexes of graph homomorphisms, Israel J. Math.152 (2006), 285–312.

    Article  MATH  MathSciNet  Google Scholar 

  3. Eric Babson and Dmitry N. Kozlov: Proof of the Lovász Conjecture, Annals of Mathematics165(3) (2007), 965–1007.

    Article  MATH  MathSciNet  Google Scholar 

  4. Graham R. Brightwell and Peter Winkler: Graph homomorphisms and long range action, in: Graphs, morphisms and statistical physics, volume 63 of DIMACS Ser. Discrete Math. Theoret. Comput. Sci., pages 29–47. Amer. Math. Soc., Providence, RI, 2004.

    Google Scholar 

  5. Péter Csorba: Homotopy types of box complexes, Combinatorica27(6) (2007), 669–682.

    Article  MATH  MathSciNet  Google Scholar 

  6. Anton Dochtermann: Hom complexes and homotopy theory in the category of graphs, European J. Combin.30(2) (2009), 490–509.

    Article  MATH  MathSciNet  Google Scholar 

  7. Dmitry N. Kozlov: Collapsing along monotone poset maps, Int. J. Math. Math. Sci.2006 (2006), Art. ID 79858, 8 pages.

  8. Dmitry N. Kozlov: Chromatic numbers, morphism complexes, and Stiefel-Whitney characteristic classes; in: Geometric combinatorics, volume 13 of IAS/Park City Math. Ser., pages 249–315, Amer. Math. Soc., Providence, RI, 2007.

    Google Scholar 

  9. László Lovász: Kneser’s conjecture, chromatic number, and homotopy; J. Combin. Theory Ser. A25(3) (1978), 319–324.

    Article  MATH  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Anton Dochtermann.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Dochtermann, A. The universality of Hom complexes of graphs. Combinatorica 29, 433–448 (2009). https://doi.org/10.1007/s00493-009-2376-7

Download citation

  • Received:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00493-009-2376-7

Mathematics Subject Classification (2000)

Navigation