The flat cover conjecture, saying that every module has a flat (pre)cover, has been recently proved by Bican, El Bashir, and Enochs. We relate flat precovers (and cotorsion preenvelopes) to weak factorizations and prove that flat monomorphisms form a left part of a weak factorization system.
Brown representability and flat covers
β Scribed by Henning Krause
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 66 KB
- Volume
- 157
- Category
- Article
- ISSN
- 0022-4049
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β¦ Synopsis
We exhibit a surprising connection between the following two concepts: Brown representability which arises in stable homotopy theory, and at covers which arise in module theory. It is shown that Brown representability holds for a compactly generated triangulated category if and only if for every additive functor from the category of compact objects into the category of abelian groups a at cover can be constructed in a canonical way. The proof also shows that Brown representability for objects and morphisms is a consequence of Brown representability for objects and isomorphisms.
π SIMILAR VOLUMES
In the general setting of Grothendieck categories with enough projectives, we prove theorems that make possible to restrict the study of the problem of the existence of -covers and envelopes to the study of some properties of the class . We then prove the existence of flat covers and cotorsion envel