COTORSION DIMENSIONS OVER GROUP RINGS
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Abstract:
Let $Gamma$ be a group, $Gamma'$ a subgroup of $Gamma$ with finite index and $M$ be a $Gamma$-module. We show that $M$ is cotorsion if and only if it is cotorsion as a $Gamma'$-module. Using this result, we prove that the global cotorsion dimensions of rings $ZGamma$ and $ZGamma'$ are equal.
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Journal title
volume 7 issue 1
pages 25- 32
publication date 2019-09-01
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