| Title: | Two-cardinal splitting (English) |
| Author: | Hrušák, Michael |
| Author: | Castro, Yhon J. |
| Language: | English |
| Journal: | Commentationes Mathematicae Universitatis Carolinae |
| ISSN: | 0010-2628 (print) |
| ISSN: | 1213-7243 (online) |
| Volume: | 66 |
| Issue: | 1 |
| Year: | 2025 |
| Pages: | 81-86 |
| Summary lang: | English |
| . | |
| Category: | math |
| . | |
| Summary: | We introduce and study a version of the classical splitting numbers $\mathfrak{s}(\kappa)$ with two parameters $\kappa\leq\lambda$ denoted by $\mathfrak{s}(\kappa,\lambda)$ and defined as the minimal size of a family $\mathcal S$ of subsets of $\lambda$ such that for every subset $A$ of $\lambda$ of size $\kappa$ there is an $S\in\mathcal S$ such that $|A\cap S|=|A\setminus S|=\kappa$. We focus on the cases when $\kappa=\mu^+$ and $\lambda=\mu^{++}$. We give several results that only depend on cardinal arithmetic, in particular, on the value that $2^{\kappa}$ assumes. (English) |
| Keyword: | two cardinal splitting |
| MSC: | 03E05 |
| MSC: | 03E10 |
| MSC: | 03E17 |
| DOI: | 10.14712/1213-7243.2025.015 |
| . | |
| Date available: | 2026-05-15T05:56:57Z |
| Last updated: | 2026-05-18 |
| Stable URL: | http://hdl.handle.net/10338.dmlcz/153613 |
| . | |
| Reference: | [1] Bağ Ö. F., Fischer V.: Strongly unfoldable, splitting and bounding.MLQ Math. Log. Q. 69 (2023), no. 1, 7–14. 10.1002/malq.202200003 |
| Reference: | [2] Ben-Neria O., Gitik M.: On the splitting number at regular cardinals.J. Symb. Log. 80 (2015), no. 4, 1348–1360. 10.1017/jsl.2015.22 |
| Reference: | [3] Brendle J.: The higher Cichoń diagram in the degenerate case.Tsukuba J. Math. 46 (2022), no. 2, 255–269. 10.21099/tkbjm/20224602255 |
| Reference: | [4] Jech T.: Set Theory.Springer Monographs in Mathematics, Springer, Berlin, 2003. Zbl 1007.03002 |
| Reference: | [5] Kunen K.: Set Theory.An Introduction to Independence Proofs, Studies in Logic and the Foundations of Mathematics, 102, North-Holland Publishing Co., Amsterdam, 1983. Zbl 0960.03033 |
| Reference: | [6] Raghavan D., Shelah S.: Two inequalities between cardinal invariants.Fund. Math. 237 (2017), no. 2, 187–200. 10.4064/fm253-7-2016 |
| Reference: | [7] Suzuki T.: On splitting numbers.Mathematical Logic and Applications '92, Kyoto, 1992, Sūrikaisekikenkyūsho Kōkyūroku 818 (1993), 118–120. |
| Reference: | [8] Suzuki T.: About splitting numbers.Proc. Japan Acad. Ser. A Math. Sci. 74 (1998), no. 2, 33–35. 10.3792/pjaa.74.33 |
| Reference: | [9] Zapletal J.: Splitting number at uncountable cardinals.J. Symbolic Logic 62 (1997), no. 1, 35–42. 10.2307/2275730 |
| . |
Fulltext not available (moving wall 24 months)