Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-10T09:50:09.406Z Has data issue: false hasContentIssue false

Partition properties and Prikry forcing on simple spaces

Published online by Cambridge University Press:  12 March 2014

J. M. Henle*
Affiliation:
Department of Mathematics, Smith College, Northampton, Massachusetts 01063

Extract

One of the simplest and yet most fruitful ideas in forcing was the notion of Karel Prikry in which he used a measure on a cardinal κ to change the cofinality of κ to ω without collapsing it. The idea has found connections to almost every branch of modern set theory, from large cardinals to small, from combinatorics to models, from Choice to Determinacy, and from consistency to inconsistency. The long list of generalizers and modifiers includes Apter, Gitik, Henle, Spector, Shelah, Mathias, Magidor, Radin, Blass and Kimchi.

This paper is about generalizing Prikry forcing and partition properties to “simple spaces”. The concept of a simple space is itself the generalization of those combinatorial objects upon which the notions of “measurable”, “compact”, “supercompact”, “huge”, etc. are based. Simple spaces were introduced in [ADHZ1] and [ADHZ2] together with a broader generalization, “filter spaces”. The definition provided here is a small simplification of earlier versions. The author is indebted to Mitchell Spector, whose careful reading turned up numerous errors, some subtle, some flagrant.

In this first section, we review simple spaces briefly, including a short introduction to the space Qκλ. In §2, we describe our generalizations of partition property and Prikry forcing, and discuss the relationship between them. In §3, we find a partition property for the huge space [λ]κ, but show that Prikry forcing here is impossible. We find partition properties for Qκλ and show that Prikry forcing can be done here.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1990

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

[ADHZ1] Apter, A., Di Prisco, C. A., Henle, J., and Zwicker, W., Filter spaces. I: Towards a unified theory of large cardinal and embedding axioms, Annals of Pure and Applied Logic (to appear).Google Scholar
[ADHZ2] Apter, A., Di Prisco, C. A., Henle, J., and Zwicker, W., Filter spaces. II: Limit ultraproducts and iterated embeddings, Acta Cientifica Venezolana (to appear).Google Scholar
[B1] Blass, A., Orderings of ultrafilters, Doctoral Dissertation, Harvard University, Cambridge, Massachusetts, 1970.Google Scholar
[B2] Blass, A., Selective ultrafilters and homogeneity (to appear).Google Scholar
[C] Carr, D., The minimal normal filter on Pκλ, Proceedings of the American Mathematical Society, vol. 86 (1986), pp. 316320.Google Scholar
[D] Devlin, K., Some remarks on changing cofinalities, this Journal, vol. 39 (1974), pp. 2730.Google Scholar
[DU ] Di Prisco, C. A. and Uzcategui, C. E., Normal filters generated by afamily of sets, Proceedings of the American Mathematical Society, vol. 101 (1987), pp. 513518.CrossRefGoogle Scholar
[G] Gitik, M., All uncountable cardinals can be singular, Israel Journal of Mathematics, vol. 35 (1980), pp. 6188.CrossRefGoogle Scholar
[HZ] Henle, J. M. and Zwicker, W., Ultrafilters on spaces of partitions, this Journal, vol. 47 (1982), pp. 137146.Google Scholar
[KM] Kanamori, A. and Magidor, M., The evolution of large cardinal axioms in set theory, Higher set theory (Müller, G. H. and Scott, D. S., editors), Lecture Notes in Mathematics, vol. 669, Springer-Verlag, Berlin, 1978, pp. 99275.CrossRefGoogle Scholar
[Mag] Magidor, M., Changing cofinalities of cardinals, Fundamenta Mathematicae, vol. 99 (1978), pp. 6171.CrossRefGoogle Scholar
[Mat1] Mathias, A. R. D., Happy families, Annals of Mathematical Logic, vol. 12 (1977), pp. 59111.CrossRefGoogle Scholar
[Mat2] Mathias, A. R. D., On sequences generic in the sense of Prikry, Journal of the Australian Mathematical Society, vol. 15 (1973), pp. 409414.CrossRefGoogle Scholar
[Men] Menas, T. K., A combinatorial property of Pκλ, this Journal, vol. 41 (1976), pp. 225234.Google Scholar
[P] Prikry, K., Changing measurable into accessible cardinals, Dissertationes Mathematicae (Rozprawy Mathematyczne), vol. 68 (1970).Google Scholar
[R] Radin, L., Adding closed cofinal sequences to large cardinals, Ph.D. thesis, University of California, Berkeley, California, 1980.Google Scholar
[S] Shelah, S., Proper forcing, Lecture Notes in Mathematics, vol. 940, Springer-Verlag, Berlin, 1982.CrossRefGoogle Scholar