9 papers
Weakly Sigma-cotorsion rings
Manuel Cortés-Izurdiaga, Sergio Estrada, José Manuel Fresneda
We study the class of rings for which every direct sum of injective -modules is cotorsion. We call them weakly -cotorsion rings. The defining property might be seen as th…
Flatness in finitely accessible additive categories
Manuel Cortés-Izurdiaga
Motivated by some problems proposed by Cuadra and Simson related to flat objects in finitely accessible Grothendieck categories, we study flatness in the more general setting of fi…
Almost free modules, perfect decomposition and Enochs's conjecture
Manuel Cortés-Izurdiaga, Alejandro Poveda
Given a module and a regular cardinal we study various notions of -freeness and -separability. Bearing on appropriate set-theoreti…
Transfer of homological objects in exact categories via adjoint triples. Applications to functor categories
Sergio Estrada, Manuel Cortés-Izurdiaga, Sinem Odabasi
For a given family of adjoint triples between exact categories or , we show that any cotorsio…
Strongly exchange rings
Manuel Cortés-Izurdiaga, Pedro A. Guil Asensio
Two elements in a ring form a right coprime pair, written , if . Right coprime pairs have shown to be quite useful in the study of left cotor…
Reflective and coreflective subcategories
Manuel Cortés-Izurdiaga, Septimiu Crivei, Manuel Saorín
Given any additive category with split idempotents, pseudokernels and pseudocokernels, we show that a subcategory is coreflective if, and only if, it is…