Abstract
We prove that for regular cardinals κ, combinations of the stick principle at κ and certain cardinal characteristics at κ being κ+ cause partition relations such as κ+ → (κ+, (κ : 2))2 and (κ+)2 → (κ+κ, 4)2 to fail. Polarised partition relations are also considered, and the results are used to answer several problems posed by Garti, Larson and Shelah.
Similar content being viewed by others
References
J. E. Baumgartner, Almost-disjoint sets, the dense set problem and the partition calculus, Annals of Mathematical Logic 9 (1976), 401–439.
J. E. Baumgartner, Remarks on partition ordinals, in Set Theory and its Applications (Toronto, ON, 1987), Lecture Notes in Mathematics, Vol. 1401, Springer, Berlin, 1989, pp. 5–17.
J. E. Baumgartner and A. Hajnal, A remark on partition relations for infinite ordinals with an application to finite combinatorics, in Logic and Combinatorics (Arcata, CA, 1985), Contemporary Mathematics, Vol. 65, AmericanMathematical Society, Providence, RI, 1987, pp. 157–167.
A. R. Blass, Combinatorial cardinal characteristics of the continuum, in Handbook of Set Theory, Vols. 1, 2, 3, Springer, Dordrecht, 2010, pp. 395–489.
J. Brendle, Cardinal invariants of the continuum and combinatorics on uncountable cardinals, Annals of Pure and Applied Logic 144 (2006), 43–72.
S. A. Broverman, J. N. Ginsburg, K. Kunen and F. D. Tall, Topologies determined by σ-ideals on ω1, Canadian Journal of Mathematics 30 (1978), 1306–1312.
P. E. Cohen, Partition generation of scales, Fundamenta Mathematicae 103 (1979), 77–82.
B. Dushnik and E. W. Miller, Partially ordered sets, American Journal of Mathematics 63 (1941), 600–610.
P. Erdős, A. Hajnal and R. Rado, Partition relations for cardinal numbers, Acta Mathematica. Academiae Scientiarum Hungaricae 16 (1965), 93–196.
P. Erdős and R. Rado, A partition calculus in set theory, Bulletin of the American Mathematical Society 62 (1956), 427–489.
P. Erdős and A. Hajnal, Ordinary partition relations for ordinal numbers, Periodica Mathematica Hungarica 1 (1971), 171–185.
P. Erdőos, A. Hajnal, A. Máté and R. Rado, Combinatorial Set Theory: Partition Relations for Cardinals, Studies in Logic and the Foundations of Mathematics, Vol. 106, North-Holland, Amsterdam, 1984.
V. Fischer and D. Soukup, More ZFC inequalities between cardinal invariants, preprint, https://arxiv.org/abs/1802.02791.
V. Fischer and J. Steprāns, The consistency of b = κ and s = κ+, Fundamenta Mathematicae 201 (2008), 283–293.
S. Fuchino, S. Shelah and L. Soukup, Sticks and clubs, Annals of Pure and Applied Logic 90 (1997), 57–77.
S. Garti and S. Shelah, Partition calculus and cardinal invariants, Journal of the Mathematical Society of Japan 66 (2014), 425–434.
S. Garti and S. Shelah, Open and solved problems concerning polarized partition relations, Fundamenta Mathematicae 234 (2016), 1–14.
S. Garti and S. Shelah, Random reals and polarized colorings, Studia Scientiarum Mathematicarum Hungarica 55 (2018), 203–212.
A. Hajnal, Some results and problems on set theory, Acta Mathematica. Academiae Scientiarum Hungaricae 11 (1960), 277–298.
A. Hajnal, A negative partition relation, Proceedings of the National Academy of Sciences of the United States of America 68 (1971), 142–144.
A. Hajnal and J. A. Larson, Partition relations, in Handbook of Set Theory. Vol. 1, Springer, Dordrecht, 2010, pp. 129–213.
L. J. Halbeisen, Combinatorial Set Theory, Springer Monographs in Mathematics, Springer, Cham, 2017.
H. Judah and S. Shelah, Killing Luzin and Sierpinski sets, Proceedings of the American Mathematical Society 120 (1994), 917–920.
K. Kunen, Set Theory, Studies in Logic and the Foundations of Mathematics, Vol. 102, North-Holland, Amsterdam, 1980.
C. Lambie-Hanson and T. V. Weinert, Partitioning subsets of generalised scattered orders, Journal of the Mathematical Society of Japan 71 (2019), 425–434.
J. A. Larson, An ordinal partition from a scale, in Set theory (Cura¸cao, 1995; Barcelona, 1996), Kluwer Academic, Dordrecht, 1998, pp. 109–125.
N. N. Luzin, Sur un probleme de M. Baire, Comptes Rendus Hebdomadaires des Séances de l’Académie des Sciences 158 (1914), 1258–1261.
D. Raghavan and S. Shelah, Two inequalities between cardinal invariants, Fundmenta Mathematicae 237 (2017), 187–200.
D. Raghavan and S. Todorcevic, Combinatorial dichotomies and cardinal invariants, Mathematical Research Letters 21 (2014), 379–401.
D. Raghavan and S. Todorcevic, Suslin trees, the bounding number, and partition relations, Israel Journal of Mathematics 225 (2018), 771–796.
S. Shelah, Colouring without triangles and partition relation, Israel Journal of Mathematics 20 (1975), 1–12.
J. Takahashi, Two negative partition relations, Periodica Mathematica Hungarica 18 (1987), 1–6.
S. Todorčević, Forcing positive partition relations, Transactions of the American Mathematical Society 280 (1983), 703–720.
S. Todorčević, Partition Problems in Topology, Contemporary Mathematics, Vol. 84, American Mathematical Society, Providence, RI, 1989.
J. K. Truss, The noncommutativity of random and generic extensions, Journal fo Symbolic Logic 48 (1983), 1008–1012.
N. H. Williams, Combinatorial Set Theory, Studies in Logic and the Foundations of Mathematics, Vol. 91, North-Holland, Amsterdam, 1977.
Author information
Authors and Affiliations
Corresponding author
Additional information
A portion of this research was undertaken while both the first and the last author were postdoctoral fellows at Ben-Gurion University of the Negev. They would like to thank Ben-Gurion University of the Negev and the Israel Science Foundation which supported this research (grant #1365/14). The second author was supported by the European Research Council, grant 338821. The last author moreover thanks the FWF for supporting him during the revision of this paper through the grants numbered I3081 and Y1012-N35.
Rights and permissions
About this article
Cite this article
Chen, W., Garti, S. & Weinert, T. Cardinal characteristics of the continuum and partitions. Isr. J. Math. 235, 13–38 (2020). https://doi.org/10.1007/s11856-019-1942-y
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11856-019-1942-y