Relative coherence and preenvelopes.
Relative exact covers
Recently Rim and Teply [11] found a necessary condition for the existence of -torsionfree covers with respect to a given hereditary torsion theory for the category -mod. This condition uses the class of -exact modules; i.e. the -torsionfree modules for which every its -torsionfree homomorphic image is -injective. In this note we shall show that the existence of -torsionfree covers implies the existence of -exact covers, and we shall investigate some sufficient conditions for the converse....
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.
Relative injectivity and CS-modules.
Relative natural classes and relative injectivity.
Relative purity over Noetherian rings
Relative theory in subcategories
We generalize the relative (co)tilting theory of Auslander-Solberg in the category mod Λ of finitely generated left modules over an artin algebra Λ to certain subcategories of mod Λ. We then use the theory (relative (co)tilting theory in subcategories) to generalize one of the main result of Marcos et al. [Comm. Algebra 33 (2005)].
Relatively exact modules
Rim and Teply [10] investigated relatively exact modules in connection with the existence of torsionfree covers. In this note we shall study some properties of the lattice of submodules of a torsionfree module consisting of all submodules of such that is torsionfree and such that every torsionfree homomorphic image of the relative injective hull of is relatively injective. The results obtained are applied to the study of relatively exact covers of torsionfree modules. As an application...
Remarks on injectivity
Remarks on Sekine quantum groups
We first describe the Sekine quantum groups (the finite-dimensional Kac algebra of Kac-Paljutkin type) by generators and relations explicitly, which maybe convenient for further study. Then we classify all irreducible representations of and describe their representation rings . Finally, we compute the the Frobenius-Perron dimension of the Casimir element and the Casimir number of .
Remarks on strongly regular rings
Remarque sur les sommes directes des modules de type dénombrable
Representable equivalences are represented by tilting modules
Representable equivalences between categories of modules and applications
Representable equivalences for closed categories of modules
Représentation d'anneaux principaux, non nécessairement commutatifs, séparés et complets pour la topologie de Krull
Representation of algebraic distributive lattices with ℵ1 compact elements as ideal lattices of regular rings.
We prove the following result: Theorem. Every algebraic distributive lattice D with at most ℵ1 compact elements is isomorphic to the ideal lattice of a von Neumann regular ring R.(By earlier results of the author, the ℵ1 bound is optimal.) Therefore, D is also isomorphic to the congruence lattice of a sectionally complemented modular lattice L, namely, the principal right ideal lattice of R. Furthermore, if the largest element of D is compact, then one can assume that R is unital, respectively,...
Representation-finite algebras and multiplicative bases.
Representations of a class of positively based algebras
We investigate the representation theory of the positively based algebra , which is a generalization of the noncommutative Green algebra of weak Hopf algebra corresponding to the generalized Taft algebra. It turns out that is of finite representative type if , of tame type if , and of wild type if In the case when , all indecomposable representations of are constructed. Furthermore, their right cell representations as well as left cell representations of are described.
Representations of étale Lie groupoids and modules over Hopf algebroids
The classical Serre-Swan's theorem defines an equivalence between the category of vector bundles and the category of finitely generated projective modules over the algebra of continuous functions on some compact Hausdorff topological space. We extend these results to obtain a correspondence between the category of representations of an étale Lie groupoid and the category of modules over its Hopf algebroid that are of finite type and of constant rank. Both of these constructions are functorially...