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A consistency result on long cardinal sequences - MaRDI portal

A consistency result on long cardinal sequences (Q2231697)

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A consistency result on long cardinal sequences
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    A consistency result on long cardinal sequences (English)
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    30 September 2021
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    This paper deals with cardinal sequences for locally compact scattered spaces; these are the sequences of cardinalities of Cantor-Bendixson levels in such spaces.\par The authors prove that given regular cardinals \(\kappa\) and \(\lambda\) and an ordinal \(\delta<\kappa^{++}\) such that \(\kappa^{++}\le\lambda\), \(\kappa^{<\kappa}\), \(2^\kappa=\kappa^+\), and \(\lambda^{\kappa^+}=\lambda\), one can force, while preserving cardinals, that \(2^\kappa=\lambda\) and there is a locally compact scattered space~\(X\) such that the set of cardinal sequences of its open subspaces contains all sequences~\(f\) of length~\(\delta\) in the cardinal interval~\([\kappa,\lambda]\) that satisfy \(f(\alpha)=\kappa\) whenever \(\operatorname{cf}\alpha<\kappa\).
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    locally compact scattered space
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    cardinal sequence
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    superatomic Boolean algebras
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