English

On coherent systems of projections for aleph_1 separable groups

Logic 2016-09-06 v1 Rings and Algebras

Abstract

It is proved consistent with either CH or the negation of CH that there is an aleph_1-separable group of cardinality aleph_1 which does not have a coherent system of projections. It had previously been shown that it is consistent with not CH that every aleph_1-separable group of cardinality aleph_1 does have a coherent system of projections.

Cite

@article{arxiv.math/9308213,
  title  = {On coherent systems of projections for aleph_1 separable groups},
  author = {Paul C. Eklof and Alan H. Mekler and Saharon Shelah},
  journal= {arXiv preprint arXiv:math/9308213},
  year   = {2016}
}
R2 v1 2026-07-22T17:54:26.028Z