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Proper Forcing, Cardinal Arithmetic, and Uncountable Linear Orders

Published online by Cambridge University Press:  15 January 2014

Justin Tatch Moore*
Affiliation:
Department of Mathematics, Boise State University, Boise, Idaho 83725, USAE-mail: [email protected]

Abstract

In this paper I will communicate some new consequences of the Proper Forcing Axiom. First, the Bounded Proper Forcing Axiom implies that there is a well ordering of ℝ which is Σ1-definable in (H(ω2), ϵ). Second, the Proper Forcing Axiom implies that the class of uncountable linear orders has a five element basis. The elements are X, ω1, , C, C * where X is any suborder of the reals of size ω1 and C is any Countryman line. Third, the Proper Forcing Axiom implies the Singular Cardinals Hypothesis at k unless stationary subsets of reflect. The techniques are expected to be applicable to other open problems concerning the theory ofH(ω2).

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2005

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References

REFERENCES

[1] Abraham, U. and Shelah, S., Isomorphism types of Aronszajn trees, Israel Journal of Mathematics, vol. 50 (1985), no. 1–2, pp. 75113.CrossRefGoogle Scholar
[2] Abraham, Uri, Rubin, Matatyahu, and Shelah, Saharon, On the consistency of some partition theorems for continuous colorings, and the structure of ℵ1 -dense real order types, Annals of Pure and Applied Logic, vol. 29 (1985), no. 2, pp. 123206.CrossRefGoogle Scholar
[3] Bagaria, Joan, Bounded forcing axioms as principles of generic absoluteness, Archive for Mathematical Logic, vol. 39 (2000), no. 6, pp. 393401.CrossRefGoogle Scholar
[4] Baumgartner, James E., All ℵ1-dense sets of reals can be isomorphic, Fundamenta Mathematicae, vol. 79 (1973), no. 2, pp. 101106.CrossRefGoogle Scholar
[5] Bekkali, M., Topics in set theory, Springer-Verlag, Berlin, 1991, Lebesgue measurabil-ity, large cardinals, forcing axioms, ρ-functions, Notes on lectures by Stevo Todorčević.CrossRefGoogle Scholar
[6] Cummings, James and Schimmerling, Ernest, Indexed squares, Israel Journal of Mathematics, vol. 131 (2002), pp. 6199.CrossRefGoogle Scholar
[7] Feng, Qi and Jech, Thomas, Projective stationary sets and a strong reflection principle, Journal of the London Mathematical Society. Second Series, vol. 58 (1998), no. 2, pp. 271283.CrossRefGoogle Scholar
[8] Foreman, Matthew, Magidor, Menachem, and Shelah, Saharon, Martin's Maximum, saturated ideals, and nonregular ultrafilters. I, Annals of Mathematics. Second Series, vol. 127 (1988), no. 1, pp. 147.CrossRefGoogle Scholar
[9] Goldstern, Martin and Shelah, Saharon, The Bounded Proper Forcing Axiom, The Journal of Symbolic Logic, vol. 60 (1995), no. 1, pp. 5873.CrossRefGoogle Scholar
[10] Gruenhage, Gary, Perfectly normal compacta, cosmic spaces, and some partition problems, Open problems in topology, North-Holland, Amsterdam, 1990, pp. 8595.Google Scholar
[11] Moore, Justin Tatch, Set mapping reflection, submitted to Journal of Mathematical Logic in 11 2003.Google Scholar
[12] Moore, Justin Tatch, A five element basis for the uncountable linear orders, Preprint, 02 2004.Google Scholar
[13] Moore, Justin Tatch, The Proper Forcing Axiom, Prikry forcing, and the Singular Cardinals Hypothesis, Preprint, 07 2004.Google Scholar
[14] Shelah, Saharon, Decomposing uncountable squares to countably many chains, Journal of Combinatorial Theory Series A, vol. 21 (1976), no. 1, pp. 110114.CrossRefGoogle Scholar
[15] Shelah, Saharon, On what I do not understand (and have something to say). I, Fundamenta Mathematicae, vol. 166 (2000), no. 1–2, pp. 182, Saharon Shelah's anniversary issue.CrossRefGoogle Scholar
[16] Shelah, Saharon, Reflection implies SCH, Preprint, 07 2004.Google Scholar
[17] Sierpinski, W., Sur unprobleme concernant les types de dimensions, Fundamenta Mathematicae, vol. 19 (1932), pp. 6571.CrossRefGoogle Scholar
[18] Silver, Jack, On the singular cardinals problem, Proceedings of the International Congress of Mathematicians (Vancouver, B.C., 1974) (Montreal, Quebec), vol. 1, Canadian Mathematics Congress, 1975, pp. 265268.Google Scholar
[19] Todorčević, Stevo, A note on the proper forcing axiom, Axiomatic set theory (Boulder, Colorado, 1983), Contempory Mathematicians, vol. 31, American Mathematical Society, Providence, RI, 1984, pp. 209218.CrossRefGoogle Scholar
[20] Todorčević, Stevo, Partitioning pairs of countable ordinals, Acta Mathematica, vol. 159 (1987), no. 3–4, pp. 261294.CrossRefGoogle Scholar
[21] Todorčević, Stevo, Partition problems in topology, American Mathematical Society, 1989.CrossRefGoogle Scholar
[22] Todorčević, Stevo, A classification of transitive relations on ω1 , Proceedings of the London Mathematical Society. Third Series, vol. 73 (1996), no. 3, pp. 501533.CrossRefGoogle Scholar
[23] Todorčević, Stevo, Localized reflection and fragments of PFA, Logic and scientific methods, DI- MACS Series in Discrete Mathematics and Theoretical Computer Science, vol. 259, American Mathematical Society, 1997, pp. 145155.CrossRefGoogle Scholar
[24] Todorčević, Stevo, Basis problems in combinatorial set theory, Proceedings of the International Congress of Mathematicians, vol. II (Berlin, 1998), vol. II, 1998, Number Extra, pp. 4352.CrossRefGoogle Scholar
[25] Todorčević, Stevo, Lipszhitz maps on trees, Technical Report 13, Institut Mittag-Leffler, 2000/2001.Google Scholar
[26] Todorčević, Stevo, Generic absoluteness and the continuum, Mathematical Research Letters, vol. 9 (2002), pp. 465472.CrossRefGoogle Scholar
[27] Todorcevic, Stevo, Coherent sequences, North-Holland, (in preparation).Google Scholar
[28] Velickovic, Boban, Forcing axioms and stationary sets, Advances in Mathematics, vol. 94 (1992), no. 2, pp. 256284.CrossRefGoogle Scholar
[29] Woodin, W. Hugh, The axiom of determinacy, forcing axioms, and the non-stationary ideal, Logic and its Applications, de Gruyter, 1999.CrossRefGoogle Scholar