Kulikov's problem on universal torsion-free abelian groups revisited

by Shelah and Struengmann. [ShSm:976]
Bulletin London Math Soc, 2011
Let T be a torsion abelian group. We consider the class of all torsion-free abelian groups G satisfying Ext (G,T)=0 and search for lambda-universal objects in this class. We show that for certain T there is no omega-universal group. However, for uncountable cardinals lambda there is always a lambda-universal group if we assume (V=L) . Together with results by the second author this solves completely a problem by Kulikov.


Back to the list of publications