Displaying 201 – 220 of 1163

Showing per page

Differentiation and splitting for lattices over orders

Wolfgang Rump (2001)

Colloquium Mathematicae

We extend our module-theoretic approach to Zavadskiĭ’s differentiation techniques in representation theory. Let R be a complete discrete valuation domain with quotient field K, and Λ an R-order in a finite-dimensional K-algebra. For a hereditary monomorphism u: P ↪ I of Λ-lattices we have an equivalence of quotient categories ̃ u : Λ - l a t / [ ] δ u Λ - l a t / [ B ] which generalizes Zavadskiĭ’s algorithms for posets and tiled orders, and Simson’s reduction algorithm for vector space categories. In this article we replace u by a more...

Ding projective and Ding injective modules over trivial ring extensions

Lixin Mao (2023)

Czechoslovak Mathematical Journal

Let R M be a trivial extension of a ring R by an R - R -bimodule M such that M R , R M , ( R , 0 ) R M and R M ( R , 0 ) have finite flat dimensions. We prove that ( X , α ) is a Ding projective left R M -module if and only if the sequence M R M R X M α M R X α X is exact and coker ( α ) is a Ding projective left R -module. Analogously, we explicitly describe Ding injective R M -modules. As applications, we characterize Ding projective and Ding injective modules over Morita context rings with zero bimodule homomorphisms.

Direct sums of semi-projective modules

Derya Keskin Tütüncü, Berke Kaleboğaz, Patrick F. Smith (2012)

Colloquium Mathematicae

We investigate when the direct sum of semi-projective modules is semi-projective. It is proved that if R is a right Ore domain with right quotient division ring Q ≠ R and X is a free right R-module then the right R-module Q ⊕ X is semi-projective if and only if there does not exist an R-epimorphism from X to Q.

Directing components for quasitilted algebras

Flávio Coelho (1999)

Colloquium Mathematicae

We show here that a directing component of the Auslander-Reiten quiver of a quasitilted algebra is either postprojective or preinjective or a connecting component.

Distributive lattices of t-k-Archimedean semirings

Tapas Kumar Mondal (2011)

Discussiones Mathematicae - General Algebra and Applications

A semiring S in 𝕊𝕃⁺ is a t-k-Archimedean semiring if for all a,b ∈ S, b ∈ √(Sa) ∩ √(aS). Here we introduce the t-k-Archimedean semirings and characterize the semirings which are distributive lattice (chain) of t-k-Archimedean semirings. A semiring S is a distributive lattice of t-k-Archimedean semirings if and only if √B is a k-ideal, and S is a chain of t-k-Archimedean semirings if and only if √B is a completely prime k-ideal, for every k-bi-ideal B of S.

Dual modules and reflexive modules with respect to a semidualizing module

Lixin Mao (2024)

Czechoslovak Mathematical Journal

Let C be a semidualizing module over a commutative ring. We first investigate the properties of C -dual, C -torsionless and C -reflexive modules. Then we characterize some rings such as coherent rings, Π -coherent rings and FP-injectivity of C using C -dual, C -torsionless and C -reflexive properties of some special modules.

Currently displaying 201 – 220 of 1163