Cotorsion-free groups from a topological viewpoint
  We present a characterization of cotorsion-free abelian groups in terms of homomorphisms from fundamental groups of Peano continua, which aligns naturally with the generalization of slenderness to non-abelian groups. In the process, we calculate the first homology group of the Griffiths twin cone. 
Katsuya Eda, Hanspeter Fischer
math.AT