The phenomenon of periodicity, discovered by Benson and Goodearl, is linked to the
behavior of the objects of cocycles in acyclic complexes. It is known that any flat Proj …

A general principle suggests that" anything flat is a directed colimit of countably presentable
flats". In this paper, we consider resolutions and coresolutions of modules over a countably …

The discussion of almost perfect domains and their modules presented in this survey paper
is divided in two parts. In the first part the ring-theoretical properties of almost perfect …

Neat subgroups of abelian groups have been generalized to modules in essentially two
different ways (corresponding to (a) and (b) in the Introduction); they are in general …

Almost perfect commutative rings R are introduced (as an analogue of Bazzoni and Salce's
almost perfect domains) for rings with divisors of zero: they are defined as orders in …

We study the notions of n-hereditary rings and its connection to the classes of finitely n-
presented modules, FP n-injective modules, FP n-flat modules and n-coherent rings. We …

Let $ T $ be a $1 $-tilting module whose tilting torsion pair $({\mathcal T},{\mathcal F}) $ has
the property that the heart ${\mathcal H} _t $ of the induced $ t $-structure (in the derived …

It is known that tilting classes are of finite type, while cotilting classes are not always of
cofinite type. We investigate this phenomenon. By using a bijection between definable …

We show that the small and large restricted injective dimensions coincide for Cohen-
Macaulay rings of finite Krull dimension. Based on this, and inspired by the recent work of …

We make a systematic approach to (strict) Mittag-Leffler inverse system and to dual Mittag-
Leffler direct systems. This allows us to prove that a right R-module M is Mittag-Leffler with …