Sh:870

• Blass, A. R., & Shelah, S. (2006). Disjoint non-free subgroups of abelian groups. In Set theory: recent trends and applications, Vol. 17, Dept. Math., Seconda Univ. Napoli, Caserta, pp. 1–24. arXiv: math/0509406 MR: 2374760
• Abstract:
  Let G be an abelian group and let \lambda be the smallest rank of any group whose direct sum with a free group is isomorphic to G. If \lambda is uncountable, then G has \lambda pairwise disjoint, non-free subgroups. There is an example where \lambda is countably infinite and G does not have even two disjoint, non-free subgroups.
• Version 2005-09-02_11 (19p)

@incollection{Sh:870,
 author = {Blass, Andreas R. and Shelah, Saharon},
 title = {{Disjoint non-free subgroups of abelian groups}},
 booktitle = {{Set theory: recent trends and applications}},
 series = {Quad. Mat.},
 volume = {17},
 year = {2006},
 pages = {1--24},
 publisher = {Dept. Math., Seconda Univ. Napoli, Caserta},
 mrnumber = {2374760},
 mrclass = {20K20 (03E05 03E75)},
 note = {\href{https://arxiv.org/abs/math/0509406}{arXiv: math/0509406}},
 arxiv_number = {math/0509406}
}