Duality and contravariant functors in the representation theory of artin algebras

Dean, S. (2019) Duality and contravariant functors in the representation theory of artin algebras. Journal of Algebra and Its Applications, 18(6), 1950111. (doi: 10.1142/s0219498819501111)

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Abstract

We know that the model theory of modules leads to a way of obtaining definable categories of modules over a ring R as the kernels of certain functors (R-Mod)op→Ab rather than of functors R-Mod→Ab which are given by a pp-pair. This paper will give various algebraic characterizations of these functors in the case that R is an artin algebra. Suppose that R is an artin algebra. An additive functor G:(R-Mod)op→Ab preserves inverse limits and G|(R-mod)op:(R-mod)op→Ab is finitely presented if and only if there is a sequence of natural transformations (−,A)→(−,B)→G→0 for some A,B∈R-mod which is exact when evaluated at any left R-module. Any additive functor (R-Mod)op→Ab with one of these equivalent properties has a definable kernel, and every definable subcategory of R-Mod can be obtained as the kernel of a family of such functors. In the final section, a generalized setting is introduced, so that our results apply to more categories than those of the form R-Mod for an artin algebra R. That is, our results are extended to those locally finitely presented K-linear categories whose finitely presented objects form a dualizing variety, where K is a commutative artinian ring.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Dean, Mr Samuel
Authors: Dean, S.
College/School:College of Science and Engineering > School of Mathematics and Statistics > Mathematics
Journal Name:Journal of Algebra and Its Applications
Publisher:World Scientific Publishing
ISSN:0219-4988
ISSN (Online):1793-6829
Published Online:18 July 2018
Copyright Holders:Copyright © 2018 World Scientific Publishing Co Pte Ltd
First Published:First published in Journal of Algebra and Its Applications 18:1950111
Publisher Policy:Reproduced in accordance with the publisher copyright policy
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