On kernels of cellular covers
Emmanuel D. Farjoun
Hebrew University, Jerusalem, IsraelRüdiger Göbel
Universität Duisburg-Essen, GermanyYoav Segev
Ben-Gurion University, Beer-Sheva, IsraelSaharon Shelah
The Hebrew University of Jerusalem, Israel
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Abstract
In the present paper we continue to examine cellular covers of groups, focusing on the cardinality and the structure of the kernel of the cellular map . We show that in general a torsion free reduced abelian group may have a proper class of non-isomorphic cellular covers. In other words, the cardinality of the kernels is unbounded. In the opposite direction we show that if the kernel of a cellular cover of any group has certain “freeness” properties, then its cardinality is bounded by .
Cite this article
Emmanuel D. Farjoun, Rüdiger Göbel, Yoav Segev, Saharon Shelah, On kernels of cellular covers. Groups Geom. Dyn. 1 (2007), no. 4, pp. 409–419
DOI 10.4171/GGD/20