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 …

Let Λ be an artin algebra. We are going to consider full subcategories of modΛ closed under
finite direct sums and under submodules with infinitely many isomorphism classes of …

For an arbitrary ring R (always associative with 1) we denote by Mod R th category of all left
R-modules and by mod R the full subcategory of Mod R wi objects the finitely presented …

In this paper we show that how the representation theory of subcategories (of the category of
modules over an Artin algebra) can be connected to the representation theory of all modules …

Let A be an artin algebra and modA the category of finitely generated A-modules. Unless
stated to the contrary, by a subcategory C of a category we mean a full subcategory of an …

Let A be an artin algebra. By mod-A we denote the category of all finitely generated right A-
modules. A pair (I, P) of full subcategories in mod-A is called Ext-orthogonal if ExtA (P, I)= 0 …

Let A be an artin algebra. We denote by mod A the category of finitely generated left A-
modules. By a subcategory of mod A we always mean a full subcategory closed under …

We prove the following results for the subcategories of an abelian category: 1) The full
subcategory whose objects are kernels of the maps between two covariantly finite …

ON CONTRAVARIANTLY FINITE SUBCATEGORIES Claus Michael Ringel Abstract. Let A be an
artin algebra. Let / 1, /2 be contravari- ant Page 1 ON CONTRAVARIANTLY FINITE …

In the category of finitely generated modules over an artinian ring, we classify all the abelian
exact subcategories closed under predecessors or, equivalently, all the split torsion pairs …