Hostname: page-component-8448b6f56d-dnltx Total loading time: 0 Render date: 2024-04-24T12:07:56.426Z Has data issue: false hasContentIssue false

Distinguishing types of gaps in (ω)/fin

Published online by Cambridge University Press:  12 March 2014

Teruyuki Yorioka*
Affiliation:
Graduate School of Science and Technology, Kobe University, Rokkodai, Nada-Ku, Kobe 657-8501, Japan, E-mail: yorioka@kurt.scitec.kobe-u.ac.jp

Abstract

Supplementing the well known results of Kunen we show that Martin's Axiom is not sufficient to decide the existence of (ω1, ϲ)-gaps when (ϲ, ϲ)-gaps exist, that is, it is consistent with ZFC that Martin's Axiom holds and there are (ϲ, ϲ)-gaps but no (ω1, ϲ)-gaps.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2003

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

[1] Bartoszyński, T. and Judah, H., Set theory: On the structure of the real line, A. K. Peters, Wellesley, Massachusetts, 1995.Google Scholar
[2] Baumgartner, J., Iterated forcing, Surveys in set theory (Mathias, A.R.D., editor), Cambridge University Press, Cambridge, 1983, pp. 159.Google Scholar
[3] Baumgartner, J., Applications of the proper forcing axiom, Handbook of set-theoretic topology, chapter 21, North-Holland, 1984, pp. 913959.Google Scholar
[4] Dow, A., Simon, P., and Vaughan, J. E., Strong homology and the proper forcing axiom, Proceedings of the American Mathematical Society, vol. 106 (1989), pp. 821828.Google Scholar
[5] Farah, I., preprint, 2002.Google Scholar
[6] Grigorieff, S., Combinatorics on ideals and forcing. Annals of Mathematical Logic, vol. 3 (1971), pp. 363394.Google Scholar
[7] Hausdorff, F., Die Graduierung nach dem Endverlauf, Abhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften, Mathematisch-Physische Klasse, vol. 31, 1909, pp. 296334.Google Scholar
[8] Jech, T., Multiple forcing, Cambridge Tracts in Mathematics, vol. 88, Cambridge University Press, 1986.Google Scholar
[9] Judah, H., Miller, A., and Shelah, S., Sacks forcing, Laver forcing, and Martin's axiom, Archive for Mathematical Logic, vol. 31 (1992), pp. 145162.Google Scholar
[10] Kunen, K., (κ, λ*)-gaps under MA, handwritten note, 1976.Google Scholar
[11] Kunen, K., Set theory: An Introduction to Independence Proofs, Studies in Logic, vol. 102, North-Holland, 1980.Google Scholar
[12] Laver, R., Linear orders in (ω) ω under eventual dominance, Logic colloquium '78, North-Holland, 1979, pp. 299302.Google Scholar
[13] Rothberger, F., Sur les familles indénombrables de suites de nombres naturels et les problèmes concernant la propriété C, Mathematical Proceedings of Cambridge Philosophical Society, vol. 37 (1941), pp. 109126.Google Scholar
[14] Scheepers, M., Gaps in ω ω , Set theory of the reals, Israel Mathematical Conference Proceedings, vol. 6, 1993, pp. 439561.Google Scholar
[15] Shelah, S., Proper forcing, Lecture Notes in Mathematics, vol. 940, Springer, 1982.Google Scholar
[16] Shelah, S., Proper and improper forcing, 2nd ed., Springer, 1998.CrossRefGoogle Scholar
[17] Todorčević, S., Directed sets and cofinal types. Transactions of the American Mathematical Society, vol. 290 (1985), no. 2, pp. 711723.Google Scholar
[18] Todorčević, S., Partition problems in topology, Contemporary Mathematics, vol. 84, American Mathematical Society, Providence, Rhode Island, 1989.Google Scholar
[19] Todorcevic, S., The first derived limit and compactly Fσ sets, Journal of the Mathematical Society of Japan, vol. 50 (1998), no. 4, pp. 831836.Google Scholar
[20] Todorchevich, S. and Farah, I., Some applications of the method of forcing, Mathematical Institute, Belgrade and Yenisei, Moscow, 1995.Google Scholar
[21] Veličković, B., OCA and automorphisms of P(ω)/fin, Topology and its Applications, vol. 49 (1993), no. 1, pp. 113.Google Scholar