Beiträge zur Algebra und Geometrie Contributions to Algebra and Geometry Vol. 44, No. 2, pp. 451-466 (2003) |
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Realizing maps between modules over Tate cohomology ringsApostolos Beligiannis and Henning KrauseDepartment of Mathematics, University of the Aegean, 83200 Karlovassi, Samos, Greece, e-mail: abeligia@mail.otenet.gr, abeligia@aegean.gr; Fakultät für Mathematik, Universität Bielefeld, D-33501 Bielefeld, Germany, e-mail: henning@mathematik.uni-bielefeld.deAbstract: Let $G$ be a finite group and $k$ be a field. Given two representations $A$ and $B$ of $G$, we investigate when all homomorphisms $\widehat H^*(G,A)\to\widehat H^*(G,B)$ over the Tate cohomology ring $\widehat H^*(G,k)$ are of the form $\widehat H^*(G,\alpha)$ for some morphism $\alpha\colon A\to B$. We construct an extended Milnor sequence which computes the obstruction for homomorphisms $\widehat H^*(G,A)\to\widehat H^*(G,B)$ to be realizable. Full text of the article:
Electronic version published on: 1 Aug 2003. This page was last modified: 4 May 2006.
© 2003 Heldermann Verlag
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