The representation theory of a ring Δ has been studied by examining the category of
contravariant (additive) functors from the category of finitely generated left Δ-modules to the …

We study the homotopy category KN (B) of N‐complexes of an additive category B and the
derived category DN (A) of an abelian category A. First we show that both KN (B) and DN (A) …

Gabriel and Popesco [4] have proved the following: Theorem (*). Let C be an Abelian
category vrith exact direct limits. Let U∈ C, E= Hom C (U, U), ℳ E be the category of right E …

We use a definition of tensor products of functors to generalize some theorems of
homological algebra. We show that adjoint pairs of functors between additive functor …

We introduce morphisms V→ W of bicategories, more general than the original ones of
Bénabou. When V= 1, such a morphism is a category enriched in the bicategory W …

Let A and B be two rings, M be a left B, right A bimodule and be the formal triangular matrix
ring. It is known that the category of right T-modules is equivalent to the category Ω of triples …

Let $ 𝓗̃ (𝓜 _ {k})(H)^{C} _ {A} $ be the category of Doi Hom-Hopf modules, $ 𝓗̃ (𝓜 _ {k}) _ {A}
$ be the category of A-Hom-modules, and F be the forgetful functor from $ 𝓗̃ (𝓜 _ {k})(H)^{C} …

In this paper we study the structure of a class of categories having two operations which
satisfy axioms analoguos to that of rings. Such categories are called" Ann-categories". We …

By using the correspondence between locally finitely presented additive categories and
rings with enough idempotents, we study several properties of such rings in terms of the …

Introduction. The study of homologically finite subcategories has turned out to be important
in several contexts, especially in the representation theory of artin algebras. In this paper we …