The splitting number can be smaller than the matrix chaos number

Heike Mildenberger*, Saharon Shelah

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Let χ be the minimum cardinality of a subset of ω2 that cannot be made convergent by multiplication with a single Toeplitz matrix. By an application of a creature forcing we show that S-fraktur sign < χ is consistent. We thus answer a question by Vojtáš. We give two kinds of models for the strict inequality. The first is the combination of an א2-iteration of some proper forcing with adding א1 random reals. The second kind of models is obtained by adding δ random reals to a model of MA for some δ ∈ [א1, κ). It was a conjecture of Blass that S-fraktur sign = א 1 < χ = κ holds in such a model. For the analysis of the second model we again use the creature forcing from the first model.

Original languageEnglish
Pages (from-to)167-176
Number of pages10
JournalFundamenta Mathematicae
Volume171
Issue number2
DOIs
StatePublished - 2002
Externally publishedYes

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