In [7] we proved that two algebras A and F are'derived equivalent', meaning that the derived
category of modules for A is equivalent to that for F, precisely when F is isomorphic to the …

A contra variant category-equivalence between categories of right R-modules and left S-
modules (all rings have units, all modules are unitary) that contain RR, SS and are closed …

Injective covers of modules were introduced by Enochs [5] as a categorical dual of an
injective envelope and they have been investigated by many authors. The T-torsionfree …

Suppose that R is a ring and that A is a chain complex over R. Inside the derived category of
differential graded R-modules there are naturally defined subcategories of A-torsion objects …

Let R be a commutative Noetherian ring and let G be the category of modules of G-
dimension zero over R. We denote the associated stable category by G. We show that the …

We prove that certain subcategories of, consisting of complete modules having a quasi-
Verma flag with respect to a Levi subalgebra, admit a combinatorial description similar to …

On projectivity in locally presentable categories Page 1 Journal of Algebra 272 (2004) 701–710
www.elsevier.com/locate/jalgebra On projectivity in locally presentable categories J …

Given a ring A and an A-coring C, we study when the forgetful functor from the category of
right C-comodules to the category of right A-modules and its right adjoint−⊗ AC are …

In [3], Cartan and Eilenberg showed that if A is a ring (with identity element) and A and C are
two (left) A-modules, then one can define for each integer n> 0 an abelian group Extn (A, C) …

ordinary category would be the category of Y-functors from! to and V-natural transformations
between them. We present here some observations on the problem. The remarks in the …