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Universal graphs without large bipartite subgraphs

Published online by Cambridge University Press:  26 February 2010

Péter Komjáth
Affiliation:
Mathematical Institute, Hungarian Academy of Sciences, Budapest, V. Reáltanoda u. 13–15, Hungary.
János Pach
Affiliation:
Mathematical Institute, Hungarian Academy of Sciences, Budapest, V. Reáltanoda u. 13–15, Hungary.
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Abstract

Let 1 ≤ α ≤ β ≤ γ be cardinals, and let denote the class of all graphs on γ vertices having no subgraph isomorphic to Kα,β. A graph is called universal if every can be embedded into Go as a subgraph. We prove that, if α < ω ≤ γ and the General Continuum Hypothesis is assumed, then has a universal element, if, and only if, (i) γ > ω or (ii) γ = ω, α = 1 and β ≤ 3. Using the Axiom of Constructibility, we also show that there does not exist a universal graph in .

Type
Research Article
Copyright
Copyright © University College London 1984

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References

1.Chang, C. C. and Kiesler, H. J.. Model theory (North-Holland, Amsterdam, London, New York, 1973).Google Scholar
2.Devlin, K. J.. The axiom ofconstructibility, A guide for the mathematician, Lecture Notes in Mathematics, 617 (Springer, Berlin-Heidelberg-New York, 1977).Google Scholar
3.Erdos, P. and Spencer, J.. Probabilistic methods in combinatorics (Academic Press, New York-London, 1974).Google Scholar
4.Hajnal, A. and Mété, A.. Set mappings, partitions, and chromatic numbers, Logic Colloquium '73 (Bristol). Studies in Logic and the Foundations of Mathematics, 80 (North-Holland, Amsterdam, 1975), 347379.Google Scholar
5.Hajnal, A. and Pach, J.. Monochromatic paths in infinite graphs. In Finite and Infinite Sets. Coll. Math. Soc. J. Bolyai, 37 (Eger, 1981), 359369.Google Scholar
6.Rado, R.. Universal graphs and universal functions. Ada Arith., 9 (1964), 331340.CrossRefGoogle Scholar
7.Rado, R.. Universal graphs. In A Seminar in Graph Theory, (eds. Harary, and Beineke, ) (Holt, Rinehart and Winston Co., 1967).Google Scholar
8.Shelah, S.. Notes in combinatorial set theory. Israel J. Math., 14 (1973), 262277.CrossRefGoogle Scholar
9.Report on the 1980 M. Schweitzer mathematical competition (in Hungarian). Mat. Lapok, 29 (1977–1981), 349362.Google Scholar