The aim of this paper is to investigate the relationship between the Abelian groups G with Ext(G,G(κ)) D 0 and those satisfying Ext(G,G(κ)) ≈ Ext(G,G)(κ) for various cardinals κ. In particular, we will give the structure of self-Ext-small groups. Our results answer several open problems, and give new proofs of known theorems concerning splitters, tilting groups and finitely faithful S-groups. © de Gruyter 2014.
|Publication status||Published - 2014|