On group rings with restricted minimum condition.
On Groups and Endomorphism Rings.
On groups rings which are not Ore domains.
On -separable and Galois extensions of rings.
On indecomposable projective representations of finite groups over fields of characteristic p > 0
Let G be a finite group, F a field of characteristic p with p||G|, and the twisted group algebra of the group G and the field F with a 2-cocycle λ ∈ Z²(G,F*). We give necessary and sufficient conditions for to be of finite representation type. We also introduce the concept of projective F-representation type for the group G (finite, infinite, mixed) and we exhibit finite groups of each type.
On intecomposable Lattices over Twisted group rings
On isomorphic commutative group algebras of Abelian groups with -projective quotients.
On Krull dimension of Ore extensions.
On Lie algebras in braided categories
The category of group-graded modules over an abelian group is a monoidal category. For any bicharacter of this category becomes a braided monoidal category. We define the notion of a Lie algebra in this category generalizing the concepts of Lie super and Lie color algebras. Our Lie algebras have -ary multiplications between various graded components. They possess universal enveloping algebras that are Hopf algebras in the given category. Their biproducts with the group ring are noncommutative...
On lifting of idempotents and semiregular endomorphism rings
Starting with some observations on (strong) lifting of idempotents, we characterize a module whose endomorphism ring is semiregular with respect to the ideal of endomorphisms with small image. This is the dual of Yamagata's work [Colloq. Math. 113 (2008)] on a module whose endomorphism ring is semiregular with respect to the ideal of endomorphisms with large kernel.
On local weak crossed product orders
Let Λ = (S/R,α) be a local weak crossed product order in the crossed product algebra A = (L/K,α) with integral cocycle, and the inertial group of α, for S* the group of units of S. We give a condition for the first ramification group of L/K to be a subgroup of H. Moreover we describe the Jacobson radical of Λ without restriction on the ramification of L/K.
On matrix near-rings.
On matrix rings over unit-regular rings.
On McCoy condition and semicommutative rings
Let be a ring and an endomorphism of . We give a generalization of McCoy’s Theorem [ Annihilators in polynomial rings, Amer. Math. Monthly 64 (1957), 28–29] to the setting of skew polynomial rings of the form . As a consequence, we will show some results on semicommutative and -skew McCoy rings. Also, several relations among McCoyness, Nagata extensions and Armendariz rings and modules are studied.
On modular projective representations of finite nilpotent groups
Our aim is to determine necessary and sufficient conditions for a finite nilpotent group to have a faithful irreducible projective representation over a field of characteristic p ≥ 0.
On module categories with nilpotent infinite radical
On *-modules generating the injectives
On modules with Le-decomposition.
On non singular p-inyective rings.
A ring R is said to be left p-injective if, for any principal left ideal I of R, any left R-homomorphism I into R extends to one of R into itself. In this note left nonsingular left p-injective rings are characterized using their maximal left rings of quotients and the structure of semiprime left p-injective rings of bounded index is investigated.
On p.p.-rings which are reduced.