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A Gitik iteration with nearly Easton factoring

Published online by Cambridge University Press:  12 March 2014

William J. Mitchell*
Affiliation:
Department of Mathematics, University of Florida, Gainesville, Florida 32611, USA, E-mail: [email protected]

Abstract

We reprove Gitik's theorem that if the GCH holds and o(κ) = κ + 1 then there is a generic extension in which κ is still measurable and there is a closed unbounded subset C of κ such that every ν ∈ C is inaccessible in the ground model.

Unlike the forcing used by Gitik, the iterated forcing ℛλ+1 used in this paper has the property that if λ is a cardinal less then κ then ℛλ+1 can be factored in V as ℛκ+1 = ℛλ+1 × ℛλ+1,κ where ∣ℛλ+1∣ ≤ λ+ and ℛλ+1,κ does not add any new subsets of λ.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2003

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References

REFERENCES

[1]Gitik, Moti, Changing cofinalities and the nonstationary ideal, Israel Journal of Mathematics, vol. 56 (1986), no. 3, pp. 280314.CrossRefGoogle Scholar
[2]Gitik, Moti, On closed unbounded sets consisting of former regulars, this Journal, vol. 64 (1999), no. 1, pp. 112.Google Scholar
[3]Magidor, Menachim, Changing cofinality of cardinals, Fundamenta Mathematicae, vol. 99 (1978), no. 1, pp. 6171.CrossRefGoogle Scholar
[4]Mitchell, William J., How weak is a closed unbounded ultrafilter?, Logic colloquium '80 (Boffa, M., Van Dalen, D., and McAloon, K., editors), North-Holland, Amsterdam, 1982, pp. 209230.Google Scholar
[5]Mitchell, William J., Indiscernibles, skies, and ideals, Axiomatic set theory (Boulder, Colorado, 1983), 1984, pp. 161182.CrossRefGoogle Scholar
[6]Mitchell, William J., A measurable cardinal with a closed unbounded set of inaccessibles from o(κ) = κ, Transactions of the American Mathematical Society, vol. 353 (2001), pp. 48634897.CrossRefGoogle Scholar
[7]Mitchell, William J., One repeat point gives a closed, unbounded ultrafilter on ω1, 2003, In preparation.Google Scholar
[8]Prikry, Karl, Changing measurable into accessible cardinals, Dissertationes mathematicae (Rozprawy mathematycne), vol. 68, 1971, pp. 359378.Google Scholar
[9]Radin, Lon Berk, Adding closed cofinal sequences to large cardinals, Annals of Mathematical Logic, vol. 22 (1982), no. 3, pp. 243261.CrossRefGoogle Scholar