Borel Whitehead groups

1998/09/15 by Saharon Shelah, Shelah, Saharon
Mathematics · Computer Science · #Advanced Topology and Set Theory #Computability, Logic, AI Algorithms #Rings, Modules, and Algebras

paper · pdf · doi:10.48550/arxiv.math/9809198

Abstract

We investigate the Whiteheadness of Borel abelian groups (aleph₁-free, wlog, as otherwise this is trivial). We show that CH (and even WCH) implies any such abelian group is free, and always aleph₂-free.

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