An addendum and corrigendum to “Almost free splitters" (Colloq. Math. 81 (1999), 193–221)
Tom 88 / 2001
Colloquium Mathematicum 88 (2001), 155-158
MSC: Primary 13C05, 18E40, 18G05, 20K20, 20K35, 20K40; Secondary
13D30, 18G25, 20K25, 20K30, 13C10.
DOI: 10.4064/cm88-1-11
Streszczenie
Let $R$ be a subring of the rational numbers ${\mathbb Q}$. We recall from \cite{GS2} that an $R$-module $G$ is a splitter if ${\rm Ext}^1_R(G,G) = 0$. In this note we correct the statement of Main Theorem 1.5 in \cite{GS2} and discuss the existence of non-free splitters of cardinality $\aleph_1$ under the negation of the special continuum hypothesis CH.
