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On inverse categories and transfer in cohomology

Part of: Special categories Homological methods Homological algebra

Published online by Cambridge University Press:  05 December 2012

Markus Linckelmann
Markus Linckelmann*
Affiliation:
Department of Mathematical Sciences, Institute of Mathematics, University of Aberdeen, King's College, Fraser Noble Building, Aberdeen AB24 3UE, UK
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Abstract

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It follows from methods of B. Steinberg, extended to inverse categories, that finite inverse category algebras are isomorphic to their associated groupoid algebras; in particular, they are symmetric algebras with canonical symmetrizing forms.We deduce the existence of transfer maps in cohomology and Hochschild cohomology from certain inverse subcategories. This is in part motivated by the observation that, for certain categories , being a Mackey functor on is equivalent to being extendible to a suitable inverse category containing . We further show that extensions of inverse categories by abelian groups are again inverse categories.

Keywords

Inverse categorytransfercohomology

MSC classification

Secondary: 18G15: Ext and Tor, generalizations, Künneth formula 18B40: Groupoids, semigroupoids, semigroups, groups (viewed as categories) 16E40: (Co)homology of rings and algebras (e.g. Hochschild, cyclic, dihedral, etc.)

Information

Type
Research Article
Information
Proceedings of the Edinburgh Mathematical Society , Volume 56 , Issue 1 , February 2013 , pp. 187 - 210
Copyright
Copyright © Edinburgh Mathematical Society 2012

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