On the Lattice of Cotorsion Theories
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Rüdiger Göbel; Saharon Shelah; Simone L Wallutis
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Article
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2001
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Elsevier Science
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English
⚖ 181 KB
We discuss the lattice of cotorsion theories for abelian groups. First we show that the sublattice of the well-studied rational cotorsion theories can be identified with the well-known lattice of types. Using a recently developed method for making Ext vanish, we also prove that any power set togethe