Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4587445 | Journal of Algebra | 2009 | 18 Pages |
Abstract
Let A be an Artin algebra and modA be the category of finitely generated right A-modules. We prove that an additive full subcategory C of modA closed under predecessors is contravariantly finite if and only if its right Ext-orthogonal is covariantly finite, or if and only if the Ext-injectives in C define a cotilting module (over the support algebra of C) or, equivalently, if and only if C is the support of the representable functors given by the Ext-injectives.
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