On the category of commutative connected graded Hopf algebras over a perfect field
On the structure of locally finite pure semisimple Grothendieck categories
Projective abelian Hopf algebras over a field [Book]
Relative hermitian Morita theory. Part II: Hermitian Morita contexts.
We introduce the notion of a relative hermitian Morita context between torsion triples and we show how these induce equivalences between suitable quotient categories of left and right modules.Due to the lack of involutive bimodules, the induced Morita equivalences are not necessarily hermitian, however.
Representable equivalences for closed categories of modules
Tertiary decomposition in Grothendieck categories
The category of groupoid graded modules
We introduce the abelian category R-gr of groupoid graded modules and give an answer to the following general question: If U: R-gr → R-mod denotes the functor which associates to any graded left R-module M the underlying ungraded structure U(M), when does either of the following two implications hold: (I) M has property X ⇒ U(M) has property X; (II) U(M) has property X ⇒ M has property X? We treat the cases when X is one of the properties: direct summand, free, finitely generated, finitely presented,...
The Hermitian Morita theorems.
Topological linear compactness for Grothendieck categories. Theorem of Tychonoff. Applications to coalgebras.
We show the Tychonoff's theorem for a Grothendieck category with a set of small projective generators. Strictly quasi-finite objects for semiartinian Grothendieck categories are characterized. We apply these results to the study of the Morita duality of dual algebra of a coalgebra.
Weak Baer modules over graded rings
In [2], Fuchs and Viljoen introduced and classified the -modules for a valuation ring R: an R-module M is a -module if for each divisible module X and each torsion module X with bounded order. The concept of a -module was extended to the setting of a torsion theory over an associative ring in [14]. In the present paper, we use categorical methods to investigate the -modules for a group graded ring. Our most complete result (Theorem 4.10) characterizes -modules for a strongly graded ring R...
When are induction and coinduction functors isomorphic?
When is the category of flat modules abelian?
Let Fl(R) denote the category of flat right modules over an associative ring R. We find necessary and sufficient conditions for Fl(R) to be a Grothendieck category, in terms of properties of the ring R.
О формуле Кузьминова
Обобщенная категория Гротендика.