# Whitehead groups may not be free even assuming ch, II

@article{Shelah1980WhiteheadGM, title={Whitehead groups may not be free even assuming ch, II}, author={Saharon Shelah}, journal={Israel Journal of Mathematics}, year={1980}, volume={35}, pages={257-285} }

AbstractWe prove some theorems on uncountable abelian groups, and consistency results promised in the first part, and also that a variant of
$$
\diamondsuit _{\omega _1 }
$$
called ♣ (club), is consistent with 2ℵ0

#### 92 Citations

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On the Existence of Rigid ℵ1-Free Abelian Groups of Cardinality ℵ1

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Techniques of uniformization are used to prove that it is not consistent that the Whitehead groups of cardinality ℵ1 are exactly the strongly ℵ1-free groups. Some consequences of the assumption that… Expand

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The consistency of Ext(G, Z)=Q

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For abelian groups, ifV=L, Ext(G, Z) cannot have cardinality ℵ0. We show that G.C.H. does not imply this. See Hiller and Shelah [2], Hiller, Huber and Shelah [3], Nunke [5] and Shelah [6, 7, 8] for… Expand

Hedetniemi's conjecture for uncountable graphs

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