JournalsrsmupVol. 144pp. 87–104

k\aleph_k-free cogenerators

  • Manfred Dugas

    Baylor University, Waco, USA
  • Daniel Herden

    Baylor University, Waco, USA
  • Saharon Shelah

    The Hebrew University of Jerusalem, Israel and The State University of New Jersey, Piscataway, USA
$\aleph_k$-free cogenerators cover
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We prove in ZFC that an abelian group CC is cotorsion if and only if Ext(F,C)=0(F,C) = 0 for every k\aleph_k-free group FF, and discuss some consequences and related results. This short note includes a condensed overview of the λˉ\bar\lambda-Black Box for k\aleph_k-free constructions in ZFC.

Cite this article

Manfred Dugas, Daniel Herden, Saharon Shelah, k\aleph_k-free cogenerators. Rend. Sem. Mat. Univ. Padova 144 (2020), pp. 87–104

DOI 10.4171/RSMUP/58