Summary
Various questions posed by P. Nyikos concerning ultrafilters on ω and chains in the partial order (ω, <*) are answered. The main tool is the oracle chain condition and variations of it.
Similar content being viewed by others
References
Abraham, A., Rubin, M., Shelah, S.: On the consistency of some partition theorems for continuous colorings, and structure of ℵ1-dense real order types. Ann. Pure Appl. Logic29, 123–206 (1985)
Blass, A.: Applications of superperfect forcing and its relatives. In: Steprāns, J., Watson, S. (eds.) Set Theory and its Applications. (Lect. Notes Math., vol. 1401, pp. 18–40) Berlin Heidelberg New York: Springer 1989
Dow, A.: Remote points in spaces with π-weight ω1. Fund. Math.74, 197–205 (1984)
Just, W.: A modification of Shelah's oracle-c.c. with applications. Trans. Amer. Math. Soc.321 (2), 621–645 (1990)
Nyikos, P.: Special ultrafilters and cofinal subsets ofωω. (preprint)
Shelah, S.: Proper forcing. Lect. Notes Math.940 (1982)
Steprāns, J.: Combinatorial consequences of adding Cohen reals. Submitted to Proceedings of the 1991 Jerusalem conference. Set Theory of the reals, p. 19
Todorcevic, S.: Partition problems in topology. J. Am. Math. Soc.84 (1989)
Author information
Authors and Affiliations
Additional information
The first author is partially supported by the basic research fund of the Israeli Academy. The second author is partially supported by NSERC and was a guest of Rutgers University while the research on this paper was being done. The authors would also like to thank P. Nyikos for his valuable comments on early versions of this paper. This is number 465 on the first author's list of publications
Rights and permissions
About this article
Cite this article
Shelah, S., Steprāns, J. Maximal chains inωω and ultrapowers of the integers. Arch Math Logic 32, 305–319 (1993). https://doi.org/10.1007/BF01409965
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01409965