Displaying similar documents to “Generalized Lefschetz numbers of pushout maps defined on non-connected spaces”

Totally reflexive modules with respect to a semidualizing bimodule

Zhen Zhang, Xiaosheng Zhu, Xiaoguang Yan (2013)

Czechoslovak Mathematical Journal

Similarity:

Let S and R be two associative rings, let S C R be a semidualizing ( S , R ) -bimodule. We introduce and investigate properties of the totally reflexive module with respect to S C R and we give a characterization of the class of the totally C R -reflexive modules over any ring R . Moreover, we show that the totally C R -reflexive module with finite projective dimension is exactly the finitely generated projective right R -module. We then study the relations between the class of totally reflexive modules and...

QTAG torsionfree modules

Ladislav Bican, Blas Torrecillas (1992)

Commentationes Mathematicae Universitatis Carolinae

Similarity:

The structure theory of abelian p -groups does not depend on the properties of the ring of integers, in general. The substantial portion of this theory is based on the fact that a finitely generated p -group is a direct sum of cyclics. Given a hereditary torsion theory on the category R - of unitary left R -modules we can investigate torsionfree modules having the corresponding property for all torsionfree factor-modules (and a natural requirement concerning extensions of some homomorphisms)....

Characterizations of groups generated by Kronecker sets

András Biró (2007)

Journal de Théorie des Nombres de Bordeaux

Similarity:

In recent years, starting with the paper [B-D-S], we have investigated the possibility of characterizing countable subgroups of the torus T = R / Z by subsets of Z . Here we consider new types of subgroups: let K ⊆ T be a Kronecker set (a compact set on which every continuous function f : K → T can be uniformly approximated by characters of T ), and G the group generated by K . We prove (Theorem 1) that G can be characterized by a subset of Z 2 (instead of a subset of Z ). If K is finite, Theorem 1 implies our...

On Kelvin type transformation for Weinstein operator

Martina Šimůnková (2001)

Commentationes Mathematicae Universitatis Carolinae

Similarity:

The note develops results from [5] where an invariance under the Möbius transform mapping the upper halfplane onto itself of the Weinstein operator W k : = Δ + k x n ∂ ∂ x n on ℝ n is proved. In this note there is shown that in the cases k ≠ 0 , k ≠ 2 no other transforms of this kind exist and for case k = 2 , all such transforms are described.

Finitely generated almost universal varieties of 0 -lattices

Václav Koubek, Jiří Sichler (2005)

Commentationes Mathematicae Universitatis Carolinae

Similarity:

A concrete category 𝕂 is (algebraically) if any category of algebras has a full embedding into 𝕂 , and 𝕂 is if there is a class 𝒞 of 𝕂 -objects such that all non-constant homomorphisms between them form a universal category. The main result of this paper fully characterizes the finitely generated varieties of 0 -lattices which are almost universal.