Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-11T05:42:30.580Z Has data issue: false hasContentIssue false

A model in which the base-matrix tree cannot have cofinal branches

Published online by Cambridge University Press:  12 March 2014

Peter Lars Dordal*
Affiliation:
Department of Mathematics, Loyola University of Chicago, Chicago, Illinois 60626

Abstract

A model of ZFC is constructed in which the distributivity cardinal h is , and in which there are no ω 2-towers in [ω]ω. As an immediate corollary, it follows that any base-matrix tree in this model has no cofinal branches. The model is constructed via a form of iterated Mathias forcing, in which a mixture of finite and countable supports is used.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1987

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[B1] Balcar, B., Pelant, J., and Simon, P., The space of ultrafilters on N covered by nowhere dense sets, fundament a Mathematicae, vol. 110 (1980), pp. 1124.CrossRefGoogle Scholar
[B2] Baumgartner, J., Iterated forcing, Surveys in set theory (Mathias, A.R.D., editor), London Mathematical Society Lecture Note Series, no. 87, Cambridge University Press, Cambridge, 1983, pp. 159.Google Scholar
[B3] Baumgartner, J. and Dordal, P., Adjoining dominating functions, this Journal, vol. 50 (1985), pp. 94101.Google Scholar
[D1] Dordal, P., Independence results concerning some combinatorial properties of the continuum, Ph.D. Dissertation, Harvard University, Cambridge, Massachusetts, 1982.Google Scholar
[D2] van Douwen, E., The integers and topology, The handbook of set-theoretic topology (Kunen, K. and Vaughan, J., editors), North-Holland, Amsterdam, 1984, pp. 111167.CrossRefGoogle Scholar
[D3] Dow, A., Tree Π-bases for βN – N in various models (to appear).Google Scholar
[H] Hausdorff, F., Summenvon ℵ1 Mengen, Fundamenta Mathematicae, vol. 26 (1936), pp. 241255.CrossRefGoogle Scholar
[J] Jech, T., Set theory, Academic Press, New York, 1978.Google Scholar
[L] Laver, R., On the consistency of Borel's conjecture, Acta Mathematica, vol. 137 (1976), 151169.Google Scholar
[M] Mitchell, W., Aronszajn trees and the independence of the transfer property, Annals of Mathematical Logic, vol. 5 (1972), pp. 2146.CrossRefGoogle Scholar