A projective characterization for SKT-modules
Abstract: In this paper a class of abelian groups (SKT-modules), which includes the torsion totally projective groups, S-groups, and balanced projectives is shown to be a subclass of a projective class of groups with respect to a naturally defined class of short exact sequences called the ch-projective modules and ch-pure sequences, respectively. Every -module has a ch-pure projective resolution and every reduced ch-projective module is a summand of a SKT-module. It is finally shown that a -module M is ch-projective if and only if, for every ordinal , the two -modules and are both ch-projective.
-  R. B. Warfield Jr., A classification theorem for abelian 𝑝-groups, Trans. Amer. Math. Soc. 210 (1975), 149–168. MR 0372071, https://doi.org/10.1090/S0002-9947-1975-0372071-2
-  R. B. Warfield Jr., Classification theory of abelian groups. I. Balanced projectives, Trans. Amer. Math. Soc. 222 (1976), 33–63. MR 0422455, https://doi.org/10.1090/S0002-9947-1976-0422455-X
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