4 papers · 1 filter
Indecomposable almost free modules - the local case
Rüdiger Göbel, Saharon Shelah
Let R be a countable, principal ideal domain which is not a field and A be a countable R-algebra which is free as an R-module. Then we will construct an aleph_1-free R-module G of…
Groups isomorphic to all their non-trivial normal subgroups
Rüdiger Göbel, Agnes T. Paras, Saharon Shelah
In answer to a question of P. Hall, we supply another construction of a group which is isomorphic to each of its non-trivial normal subgroups.
Decompositions of Reflexive Modules
Ruediger Goebel, Saharon Shelah
We continue [GbSh:568] (math.LO/0003164), proving a stronger result under the special continuum hypothesis (CH). The original question of Eklof and Mekler related to dual abelian g…
Some Nasty Reflexive Groups
Ruediger Goebel, Saharon Shelah
In "Almost Free Modules, Set-theoretic Methods", Eklof and Mekler raised the question about the existence of dual abelian groups G which are not isomorphic to Z+G. Recall that G is…