Beiträge zur Algebra und Geometrie Contributions to Algebra and Geometry Vol. 51, No. 1, pp. 209227 (2010) 

Projectivity and flatness over the colour endomorphism ring of a finitely generated graded comoduleT. Guédénon110 Penworth Drive S.E., Calgary, AB, T2A 5H4, Canada, email: guedenth@yahoo.caAbstract: Let $k$ be a field, $G$ an abelian group with a bicharacter, $A$ a colour algebra; i.e., an associative graded $k$algebra with identity, $\mathcal{C}$ a graded $A$coring that is projective as a right $A$module, ${\mathcal{C}}^*$ the graded dual ring of ${\mathcal{C}}$ and $\Lambda$ a left graded $\mathcal{C}$comodule that is finitely generated as a graded right ${\mathcal C}^*$module. We give necessary and sufficient conditions for projectivity and flatness of a graded module over the colour endomorphism ring $^{\mathcal{C}}END(\Lambda)$. Full text of the article:
Electronic version published on: 27 Jan 2010. This page was last modified: 28 Jan 2013.
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