ArticleOriginal scientific text
Title
Weakly normal ideals ou PKl and the singular cardinal hypothesis
Authors 1, 2
Affiliations
- Numazu College of Technology, 3600 Ooka, Numazu-Shi, Shizuoka, 410 Japan
- Department of Mathematics, Kanagawa University, Rokkakubashi, Kanagawa-Ku, Yokohama 221, Japan
Abstract
In §1, we observe that a weakly normal ideal has a saturation property; we also show that the existence of certain precipitous ideals is sufficient for the existence of weakly normal ideals. In §2, generalizing Solovay's theorem concerning strongly compact cardinals, we show that is decided if carries a weakly normal ideal and λ is regular or cf λ ≤ κ. This is applied to solving the singular cardinal hypothesis.
Bibliography
- Y. Abe, Weakly normal filters and the closed unbounded filter on
, Proc. Amer. Math. Soc. 104 (1988), 1226-1234. - Y. Abe, Saturated ideals and subtle properties of
, circulated. - Y. Abe, Weakly normal filters and large cardinals, Tsukuba J. Math. 16 (1992), 487-494.
- D. M. Carr, The minimal normal filter on
, Proc. Amer. Math. Soc. 86 (1982), 316-320. - M. Foreman, Potent axioms, Trans. Amer. Math. Soc. 294 (1986), 1-28.
- C. A. Johnson, On ideals and stationary reflection, J. Symbolic Logic 54 (1989), 568-575.
- A. Kanamori, Weakly normal filters and irregular ultrafilters, Trans. Amer. Math. Soc. 220 (1976), 393-399.
- Y. Matsubara, Menas's conjecture and generic ultrapowers, Ann. Pure Appl. Logic 36 (1987), 225-234.
- Y. Matsubara, private communication.
- R. Mignone, A direct weakening of normality for filters, preprint.
- M. Shioya, Weakly normal closures of filters on
, to appear. - J. Silver, On the singular cardinals problem, in: Proc. Internat. Congress Math. Vancouver, 1974, 265-268.
- R. M. Solovay, Real-valued measurable cardinals, in: Axiomatic Set Theory, Proc. Sympos. Pure Math. 13 I, D. Scott (ed.), Amer. Math. Soc., Providence, R.I., 1971, 397-428.
- R. M. Solovay, Strongly compact cardinals and the GCH, in: Proc. Tarski Symposium, Proc. Sympos. Pure Math. 25, Amer. Math. Soc., Providence, R.I., 1974, 365-372.
- R. M. Solovay, W. N. Reinhardt and A. Kanamori, Strong axioms of infinity and elementary embeddings, Ann. Math. Logic 13 (1978), 73-116.
Additional information
http://matwbn.icm.edu.pl/ksiazki/fm/fm143/fm14321.pdf