Abstract
We show that the existence of atomlessly measurable cardinals is incompatible with the existence of well-orderings of the reals in L(ℝ), but consistent with the existence of well-orderings of the reals that are third-order definable in the language of arithmetic. Specifically, we provide a general argument that, starting from a measurable cardinal, produces a forcing extension where c is real-valued measurable and there is a Δ 22 -well-ordering of ℝ. A variation of this idea, due to Woodin, gives Σ 21 -well-orderings when applied to L[μ] or, more generally, Σ 21 (Hom∞) if applied to nice inner models, provided enough large cardinals exist in V. We announce a recent result of Woodin indicating how to transform this variation into a proof from large cardinals of the Ω-consistency of real-valued measurability of c together with the existence of Σ 21 -definable well-orderings of ℝ. It follows that if the Ω-conjecture is true, and large cardinals are granted, then this statement can always be forced.
However, we introduce a strengthening of real-valued measurability (real-valued hugeness), show its consistency, and prove that it contradicts the existence of third-order definable well-orderings of ℝ.
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References
U. Abraham, S. Shelah. Forcing closed unbounded sets, The Journal of Symbolic Logic 48(3) (1983), 643–657 ([AbSh 146]).
U. Abraham, S. Shelah. A Δ 22 well-order of the reals and incompactness of L(Q MM), Annals of Pure and Applied Logic 59(1) (1993), 1–32 ([AbSh 403]).
U. Abraham, S. Shelah. Martin’s Axiom and Δ 21 well-ordering of the reals, Archive for Mathematical Logic 35(5–6) (1996), 287–298 ([AbSh 458]).
U. Abraham, S. Shelah. Coding with ladders a well ordering of the reals, The Journal of Symbolic Logic 67(2) (2002), 579–597 ([AbSh 485]).
J. Bagaria, N. Castells, and P. Larson. An Ω-logic primer, this volume.
B. Balcar, T. Jech, and J. Zapletal. Semi-Cohen Boolean algebras, Annals of Pure and Applied Logic 87 (1997), 187–208.
S. Banach, K. Kuratowski. Sur une généralisation du problème de la mesure, Fundamenta Mathematicae 14 (1929), 127–131.
T. Bartoszyński, H. Judah. Set Theory. On the structure of the real line, A.K. Peters (1995).
J. Baumgartner. Iterated Forcing, in Surveys in Set Theory, A.D.R. Mathias, ed., Cambridge University Press (1983), 1–59.
J. Baumgartner. Applications of the Proper Forcing Axiom, in Handbook of Set-Theoretic Topology, K. Kunen and J.E. Vaughan, eds., Elsevier Science Publishers (1984), 913–959.
A. Caicedo. Simply definable well-orderings of the reals, Ph.D. Dissertation, Department of Mathematics, University of California, Berkeley (2003).
A. Caicedo. The strength of real-valued huge cardinals, in preparation.
J. Cummings. A model where GCH holds at successors but fails at limits, Transactions of the American Mathematical Society 329(1) (1992), 1–39.
J. Cummings. Iterated Forcing and Elementary Embeddings, to appear in Handbook of Set Theory, M. Foreman, A. Kanamori, and M. Magidor, eds., to appear.
A. Dodd. the Core Model, Cambridge University Press (1982).
Q. Feng, M. Magidor, and H. Woodin. Universally Baire sets of reals, in Set Theory of the continuum, H. Judah, W. Just, and H. Woodin, eds., Springer-Verlag (1992), 203–242.
D. fremlin. Consequences of Martin’s Axiom, Cambridge University Press (1984).
D. Fremlin. Measure Algebras, in Handbook of Boolean Algebras, volume 3, J. Monk and R. Bonnet, eds., North-Holland (1989), 877–980.
D. Fremlin. Real-valued measurable cardinals in Set Theory of the Reals, H. Judah, ed., Israel Mathematical Conference Proceedings 6, Bar-Ilan University (1993), 151–304.
S. Fuchino. Open Coloring Axiom and Forcing Axioms, preprint.
M. Gitik, S. Shelah. Forcing with ideals and simple forcing notions, Israel Journal of Mathematics 68 (1989), 129–160 ([GiSh 357]).
M. Gitik, S. Shelah. More on Real-valued measurable cardinals and forcing with ideals, Israel Journal of Mathematics 124 (2001), 221–242 ([GiSh 582]).
J. Hamkins. Lifting and extending measures by forcing: fragile measurability, Ph.D. Dissertation, Department of Mathematics, University of California, Berkeley (1994).
T. Jech. Set Theory, Academic Press (1978).
R. Jensen. Measurable cardinals and the GCH, in Axiomatic set theory (Proc. Sympos. Pure Math., Vol. XIII, Part II, Univ. California, Los Angeles, Calif., 1967), American Mathematical Society (1974), 175–178.
A. Kanamori. The Higher Infinite, Springer-Verlag (1994).
S. Koppelberg. General Theory of Boolean Algebras, volume 1 of Handbook of Boolean Algebras, J. Monk and R. Bonnet, eds., North-Holland (1989).
S. Koppelberg. Characterizations of Cohen algebras, in Papers on general topology and applications: Seventh Conference at the University of Wisconsin, S. Andima, R. Kopperman, P. Misra, M.E. Rudin, and A. Todd, eds., Annals of the New York Academy of Sciences 704 (1993), 222–237.
S. Koppelberg, S. Shelah. Subalgebras of Cohen algebras need not be Cohen, in Logic: From Foundations to Applications. European Logic Colloquium, W. Hodges, M. Hyland, C. Steinhorn, and J. Truss, eds., Oxford University Press (1996) ([KpSh 504]).
K. Kunen. Saturated ideals, The Journal of Symbolic Logic 43(1) (1978), 65–76.
K. Kunen. Set Theory. An introduction to independence proofs, Elsevier Science Publishers (1980).
K. Kunen. Random and Cohen reals, in Handbook of Set-Theoretic Topology, K. Kunen and J.E. Vaughan, eds., Elsevier Science Publishers (1984), 887–911.
P. Larson. The Stationary Tower: Notes on a Course by W. Hugh Woodin, American Mathematical Society (2004).
P. Larson. Forcing over models of determinacy, preprint. To appear in Handbook of Set Theory, M. Foreman, A. Kanamori, and M. Magidor, eds.
A. Levy. A hierarchy of formulas in set theory, Memoirs of the American Mathematical Society 57 (1965).
D. Martin, J. Steel. Iteration trees, Journal of the American Mathematical Society 7(1) (1994), 1–73.
J. Roitman. Adding a random or a Cohen real: topological consequences and the effect on Martin’s axiom, Fundamenta Mathematicae 103(1) (1979), 47–60.
R. Solovay. Real-valued measurable cardinals, in Axiomatic set theory, Part I, American Mathematical Society (1971), 397–428.
J. Steel. The derived model theorem, preprint.
J. Steel. The core model iterability problem, Springer-Verlag (1996).
S. Todorčević. Remarks on chain conditions in products, Compositio Mathematica 55(3) (1985), 295–302.
S. Todorčević. Trees and linearly ordered sets in Handbook of Set-Theoretic Topology, K. Kunen and J.E. Vaughan, eds., Elsevier Science Publishers (1984), 235–294.
S. Ulam. Zur Masstheorie in der allgemeinen Mengenlehre, Fundamenta Mathematicae 16 (1930), 140–150.
H. Woodin. The Axiom of Determinacy, Forcing Axioms, and the Nonstationary Ideal, Walter de Gruyter (1999).
H. Woodin. The Continuum Hypothesis and the Ω-conjecture, slides of a talk given at the Fields Institute during the Thematic Program on Set Theory and Analysis, September–December 2002, A. Dow, A. Kechris, M. Laczkovich, C. Laflamme, J. Steprans, and S. Todorčević, organizers.
H. Woodin. Set Theory after Russell; the journey back to Eden, in One hundred years of Russell’s paradox, G. Link, ed., Walter de Gruyter (2004).
H. Woodin, A. Caicedo. Real-valued measurable cardinals and Σ 21 -well-orderings of the reals, preprint.
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Caicedo, A.E. (2006). Real-valued Measurable Cardinals and Well-orderings of the Reals. In: Bagaria, J., Todorcevic, S. (eds) Set Theory. Trends in Mathematics. Birkhäuser Basel. https://doi.org/10.1007/3-7643-7692-9_4
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