On incompactness for chromatic number of graphs

@article{Shelah2012OnIF,
  title={On incompactness for chromatic number of graphs},
  author={Saharon Shelah},
  journal={Acta Mathematica Hungarica},
  year={2012},
  volume={139},
  pages={363-371}
}
  • S. Shelah
  • Published 1 May 2012
  • Mathematics
  • Acta Mathematica Hungarica
We deal with incompactness. Assume the existence of non-reflecting stationary set of cofinality κ. We prove that one can define a graph G whose chromatic number is >κ, while the chromatic number of every subgraph G′⫅G, |G′|<|G| is ≦κ. The main case is κ=ℵ0. 
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LIST OF PUBLICATIONS
1. Sh:a Saharon Shelah. Classification theory and the number of nonisomorphic models, volume 92 of Studies in Logic and the Foundations of Mathematics. North-Holland Publishing Co., Amsterdam-New

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