Page 1

Displaying 1 – 10 of 10

Showing per page

Bases of minimal elements of some partially ordered free abelian groups

Pavel Příhoda (2003)

Commentationes Mathematicae Universitatis Carolinae

In the present paper, we will show that the set of minimal elements of a full affine semigroup A 0 k contains a free basis of the group generated by A in k . This will be applied to the study of the group K 0 ( R ) for a semilocal ring R .

Behavior of countably generated pure-projective modules.

Goro Azumaya (1992)

Publicacions Matemàtiques

We first prove that every countably presented module is a pure epimorphic image of a countably generated pure-projective module, and by using this we prove that if every countably generated pure-projective module is pure-injective then every module is pure-injective, while if in any countably generated pure-projective module every countably generated pure-projective pure submodule is a direct summand then every module is pure-projective.

Bicovariant differential calculi and cross products on braided Hopf algebras

Yuri Bespalov, Bernhard Drabant (1997)

Banach Center Publications

In a braided monoidal category C we consider Hopf bimodules and crossed modules over a braided Hopf algebra H. We show that both categories are equivalent. It is discussed that the category of Hopf bimodule bialgebras coincides up to isomorphism with the category of bialgebra projections over H. Using these results we generalize the Radford-Majid criterion and show that bialgebra cross products over the Hopf algebra H are precisely described by H-crossed module bialgebras. In specific braided monoidal...

Bi-ideals in k-regular and intra k-regular semirings

Anjan K. Bhuniya, Kanchan Jana (2011)

Discussiones Mathematicae - General Algebra and Applications

Here we introduce the k-bi-ideals in semirings and the intra k-regular semirings. An intra k-regular semiring S is a semiring whose additive reduct is a semilattice and for each a ∈ S there exists x ∈ S such that a + xa²x = xa²x. Also it is a semiring in which every k-ideal is semiprime. Our aim in this article is to characterize both the k-regular semirings and intra k-regular semirings using of k-bi-ideals.

Bipartite coalgebras and a reduction functor for coradical square complete coalgebras

Justyna Kosakowska, Daniel Simson (2008)

Colloquium Mathematicae

Let C be a coalgebra over an arbitrary field K. We show that the study of the category C-Comod of left C-comodules reduces to the study of the category of (co)representations of a certain bicomodule, in case C is a bipartite coalgebra or a coradical square complete coalgebra, that is, C = C₁, the second term of the coradical filtration of C. If C = C₁, we associate with C a K-linear functor C : C - C o m o d H C - C o m o d that restricts to a representation equivalence C : C - c o m o d H C - c o m o d s p , where H C is a coradical square complete hereditary bipartite...

Bound quivers of three-separate stratified posets, their Galois coverings and socle projective representations

Stanisław Kasjan (1993)

Fundamenta Mathematicae

A class of stratified posets I * ϱ is investigated and their incidence algebras K I * ϱ are studied in connection with a class of non-shurian vector space categories. Under some assumptions on I * ϱ we associate with I * ϱ a bound quiver (Q, Ω) in such a way that K I * ϱ K ( Q , Ω ) . We show that the fundamental group of (Q, Ω) is the free group with two free generators if I * ϱ is rib-convex. In this case the universal Galois covering of (Q, Ω) is described. If in addition I ϱ is three-partite a fundamental domain I * + × of this covering is...

Currently displaying 1 – 10 of 10

Page 1