English

On the p-rank of Ext(A,B) for countable abelian groups A and B

Group Theory 2014-01-22 v1

Abstract

In this note we show that the p-rank of Ext(A,B) for countable torsion-free abelian groups A and B is either countable or the size of the continuum.

Keywords

Cite

@article{arxiv.1401.5317,
  title  = {On the p-rank of Ext(A,B) for countable abelian groups A and B},
  author = {Lutz Struengmann and Saharon Shelah},
  journal= {arXiv preprint arXiv:1401.5317},
  year   = {2014}
}