Results 21 to 30 of about 600 (183)

Cohomological Dimension of an Abelian Monoid [PDF]

Proceedings of the American Mathematical Society, 1980
It is shown that the cohomological dimension of an abelian monoid is equal to that of its group reflection provided that the monoid is either finitely generated or cancellative.
Cheng, Charles Ching-An, Shapiro, Jay
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Cohomological approach to asymptotic dimension [PDF]

Geometriae Dedicata, 2008
30 ...
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Characterizing cohomological dimension: The cohomological dimension of A ∪ B

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.
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Completion Theorem for Cohomological Dimensions [PDF]

Proceedings of the American Mathematical Society, 1995
We prove that for every separable metrizable space X with dim G X ≤ n {\dim _G}X \leq n , there exists a metrizable completion Y of X with dim G Y ≤ n {\dim _G}Y \leq n
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Postulation of schemes of length at most 4 on surfaces

Bulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.
Abstract In this paper, we address the postulation problem of zero‐dimensional schemes of length at most 4 on a surface. We prove some general results and then we focus on the case of P2$\mathbb {P}^2$, P1×P1$\mathbb {P}^1\times \mathbb {P}^1$ and Hirzebruch surfaces. In particular, we prove that except for few well‐known exceptions, a general union of
Edoardo Ballico, Stefano Canino
wiley   +1 more source

Cohomological Dimension and Metrizable Spaces [PDF]

Transactions of the American Mathematical Society, 1993
Since the days of M. F. Bockstein's classical paper one tries to establish for a given abelian group \(G\) a so-called Bockstein basis \(\sigma(G)\) consisting of groups of the form \(\mathbb{Q},\mathbb{Z}_ p,\mathbb{Z}/p,\mathbb{Z}/p^ \infty\). Having the property that \(\dim_ GX\) is determined by \(\dim_ H\) for \(H\in\sigma(G)\).
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Simplification of exponential factors of irregular connections on P1${\mathbb {P}}^1$

Bulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.
Abstract We give an explicit algorithm to reduce the ramification order of any exponential factor of an irregular connection on P1$\mathbb {P}^1$, using the same types of basic operations as in the Katz–Deligne–Arinkin algorithm for rigid irregular connections.
Jean Douçot
wiley   +1 more source

Trivialité des groupes de Whitehead réduits avec applications à l’approximation faible et l’approximation forte

Comptes Rendus. Mathématique
We prove some triviality results for reduced Whitehead groups and reduced unitary Whitehead groups for division algebras over a Henselian discrete valuation field whose residue field has virtual cohomological dimension or separable dimension $\le 2 ...
Hu, Yong, Tian, Yisheng
doaj   +1 more source

Gorenstein Homological Dimension of Groups Through Flat-Cotorsion Modules [PDF]

Mathematics Interdisciplinary Research
‎The representation theory of groups is one of the most interesting examples of the interaction between physics and pure mathematics‎, ‎where group rings play the main role‎.
Ali Hajizamani
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Diophantine and cohomological dimensions [PDF]

Proceedings of the American Mathematical Society, 2015
We give explicit linear bounds on the p-cohomological dimension of a field in terms of its Diophantine dimension. In particular, we show that for a field of Diophantine dimension at most 4, the 3-cohomological dimension is less than or equal to the Diophantine dimension.
Krashen, Daniel, Matzri, Eliyahu
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