Results 161 to 170 of about 1,113 (200)

Characterizing cohomological dimension: The cohomological dimension of A ∪ B [PDF]

Topology and Its Applications, 1991
The Menger-Urysohn sum formula is proved for cohomological dimension with respect to integers. The proof is based on a characterization of cohomological dimension \(\dim_{\mathbb{Z}}\) given by the author for metrizable spaces. That characterization is the natural transfer of Edward's characterization of \(\dim_{\mathbb{Z}}\) for compact metric spaces.
Leonard R Rubin
exaly   +3 more sources

Compactifications and cohomological dimension [PDF]

Topology and Its Applications, 1993
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Jerzy Dydak
exaly   +3 more sources

On the Gorenstein cohomological dimension of group extensions [PDF]

Journal of Algebra, 2022
The Gorenstein cohomological dimension is defined for any group G and coincides with the virtual cohomological dimension vcdG, whenever the latter is defined and finite.
Ioannis Emmanouil
exaly   +1 more source

A note on bounded-cohomological dimension of discrete groups [PDF]

Journal of the Mathematical Society of Japan, 2017
Bounded-cohomological dimension of groups is a relative of classical cohomological dimension, defined in terms of bounded cohomology with trivial coefficients instead of ordinary group cohomology.
Clara Loh
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Cohomological Dimension of Complexes [PDF]

Communications in Algebra, 2004
In the derived category of the category of modules over a commutative Noetherian ring $R$, we define, for an ideal $\fa$ of $R$, two different types of cohomological dimensions of a complex $X$ in a certain subcategory of the derived category, namely $\cd(\fa, X)=\sup\{\cd(\fa, \H_{\ell}(X))-\ell|\ell\in\Bbb Z\}$ and $-\inf{\mathbf R}\G_{\fa}(X ...
Siamak Yassemi, Mohammad T Dibaei
exaly   +3 more sources

Cohomological Dimension of Generalized Local Cohomology Modules

Algebra Colloquium, 2008
The study of the cohomological dimension of algebraic varieties has produced some interesting results and problems in local algebra. Let 𝔞 be an ideal of a commutative Noetherian ring R. For finitely generated R-modules M and N, the concept of cohomological dimension cd 𝔞(M, N) of M and N with respect to 𝔞 is introduced.
Amjadi, Jafar, Naghipour, Reza
openaire   +1 more source

Cohomological dimension with respect to perfect groups [PDF]

Topology and Its Applications, 1996
We introduce new classes of compact metric spaces: Cannon—Štan'ko, Cainian, and nonabelian compacta. In particular, we investigate compacta of cohomological dimension one with respect to certain classes of nonabelian groups, e.g., perfect groups. We also
Dusan D Repovš, Alexander N Dranishnikov   +1 more
exaly   +2 more sources

On the Cohomological Dimension of Soluble Groups

Canadian Mathematical Bulletin, 1981
AbstractIt is known that every torsion-free soluble group G of finite Hirsch number hG is countable, and its homological and cohomological dimensions over the integers and rationals satisfy the inequalitiesWe prove that G must be finitely generated if the equality hG = cdQG holds.
Gildenhuys, D., Strebel, R.
openaire   +2 more sources

Periodic cohomology and subgroups with bounded Bredon cohomological dimension

Mathematical Proceedings of the Cambridge Philosophical Society, 2008
AbstractMislin and Talelli showed that a torsion-free group in$\HF$with periodic cohomology after some steps has finite cohomological dimension. In this note we look at similar questions for groups with torsion by considering Bredon cohomology. In particular we show that every elementary amenable group acting freely and properly on some$\R^n$×Smadmits ...
Jo, Jang Hyun, Nucinkis, Brita E.A.
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Cohomology with support of dimension ≤ d

Journal of Algebra and Its Applications, 2016
Let [Formula: see text] be a commutative Noetherian ring, [Formula: see text] be an integer and let [Formula: see text] denote the ideals of [Formula: see text] of dimension [Formula: see text]. For an integer [Formula: see text] and [Formula: see text]-modules [Formula: see text], we define the [Formula: see text]th cohomology module [Formula: see ...
Zamani, N., Bijan-Zadeh, M. H., Sayedsadeghi, M. S.   +2 more
openaire   +2 more sources