Canonical characters on quasi-symmetric functions and bivariate Catalan numbers.
Let G be a group, R a G-graded ring and X a right G-set. We study functors between categories of modules graded by G-sets, continuing the work of [M]. As an application we obtain generalizations of Cohen-Montgomery Duality Theorems by categorical methods. Then we study when some functors introduced in [M] (which generalize some functors ocurring in [D1], [D2] and [NRV]) are separable. Finally we obtain an application to the study of the weak dimension of a group graded ring.
Let and be two pointed sets. Given a family of three maps , this family provides an adequate decomposition of as the orthogonal disjoint union of well-described -invariant subsets. This decomposition is applied to the structure theory of graded involutive algebras, graded quadratic algebras and graded weak -algebras.
Recently, motivated by Anderson, Dumitrescu’s -finiteness, D. Bennis, M. El Hajoui (2018) introduced the notion of -coherent rings, which is the -version of coherent rings. Let be a commutative ring with unity graded by an arbitrary commutative monoid , and a multiplicatively closed subset of nonzero homogeneous elements of . We define to be graded--coherent ring if every finitely generated homogeneous ideal of is -finitely presented. The purpose of this paper is to give the graded...
The aim of this paper is to present a starting point for proving existence of injective minimal models (cf. [8]) for some systems of complete differential graded algebras.