Submission date: 2 March 2013.

Abstract:

We study (relative) K-Mittag-Leffler modules, with emphasis on the class K of absolutely pure modules. A final goal is to describe the K-Mittag-Leffler abelian groups as those that are, modulo their torsion part, aleph_1-free. Several more general results of independent interest are derived on the way. In particular, every flat K-Mittag-Leffler module (for K as before) is Mittag-Leffler. A question about the definable subcategories generated by the divisible modules and the torsion-free modules, resp., has been left open.

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Full text arXiv 1301.0961: pdf, ps.