Subgroups of the Baer–Specker group with few endomorphisms but large dual
Tom 149 / 1996
Fundamenta Mathematicae 149 (1996), 19-29
DOI: 10.4064/fm-149-1-19-29
Streszczenie
Assuming the continuum hypothesis, we construct a pure subgroup G of the Baer-Specker group $ℤ^{ℵ_0}$ with the following properties. Every endomorphism of G differs from a scalar multiplication by an endomorphism of finite rank. Yet G has uncountably many homomorphisms to ℤ.
