Results 91 to 100 of about 12,500,002 (282)
The image of the map from group cohomology to Galois cohomology
, 2011 We study the image of the natural map from group cohomology to Galois cohomology by using motivic cohomology of classifying spaces.
M. Tezuka, N. Yagita
semanticscholar +1 more source
Milan Journal of Mathematics, 2023 AbstractIn this paper we show that a finite product preserving opfibration can be factorized through an opfibration with the same property, but with groupoidal fibres. If moreover the codomain is additive, one can endow each fibre of the new opfibration with a canonical symmetric 2-group structure.
Alan S. Cigoli +2 more
openaire +2 more sources
Hilbert–Kunz multiplicity of powers of ideals in dimension two
Bulletin of the London Mathematical Society, EarlyView.Abstract We study the behavior of the Hilbert–Kunz multiplicity of powers of an ideal in a local ring. In dimension 2, we provide answers to some problems raised by Smirnov, and give a criterion to answer one of his questions in terms of a “Ratliff–Rush version” of the Hilbert–Kunz multiplicity.
Alessandro De Stefani +3 more
wiley +1 more source
Cohomology classes of rank varieties and a counterexample to a conjecture of Liu [PDF]
Discrete Mathematics & Theoretical Computer Science, 2015 To each finite subset of a discrete grid $\mathbb{N}×\mathbb{N}$ (a diagram), one can associate a subvariety of a complex Grassmannian (a diagram variety), and a representation of a symmetric group (a Specht module).
Brendan Pawlowski
doaj +1 more source
On the cohomology of Coxeter groups
Journal of Pure and Applied Algebra, 2001 AbstractIn this paper, using a result of F.T. Farrell, we reformulate the Davis formula for the cohomology of a Coxeter group, and we study the problem as to when the ith cohomology of a Coxeter group is finitely generated.
openaire +2 more sources
Presentation of kernels of rational characters of right‐angled Artin groups
Bulletin of the London Mathematical Society, EarlyView.Abstract In this note, we characterise when the kernel of a rational character of a right‐angled Artin group, also known as generalised Bestiva–Brady group, is finitely generated and finitely presented. In these cases, we exhibit a finite generating set and a presentation.
Montserrat Casals‐Ruiz +2 more
wiley +1 more source
The Hartshorne-Rao module of curves on rational normal scrolls
Le Matematiche, 2000 We study the Hartshorne-Rao module of curves lying on a rational normal scroll S_e of invariant e ≥ 0 in P^{e+3} .We calculate the Rao function, we characterize the aCM curves on S_e .Finally, we give an algorithm to check if a curve is aC M or not and ...
Roberta Di Gennaro
doaj
Type II string theory on Calabi-Yau manifolds with torsion and non-Abelian discrete gauge symmetries
Journal of High Energy Physics, 2017 We provide the first explicit example of Type IIB string theory compactification on a globally defined Calabi-Yau threefold with torsion which results in a four-dimensional effective theory with a non-Abelian discrete gauge symmetry. Our example is based
Volker Braun +3 more
doaj +1 more source
Five-term exact sequence for Kac cohomology [PDF]
Alg. Number Th. 13 (2019) 1121-1144, 2018 We use relative group cohomologies to compute the Kac cohomology of matched pairs of finite groups. This cohomology naturally appears in the theory of abelian extensions of finite dimensional Hopf algebras. We prove that Kac cohomology can be computed using relative cohomology and relatively projective resolutions.
arxiv +1 more source
Finite groups acting linearly: Hochschild cohomology and the cup product [PDF]
, 2009 When a finite group acts linearly on a complex vector space, the natural semi-direct product of the group and the polynomial ring over the space forms a skew group algebra.
Shepler, Anne V., Witherspoon, Sarah
core +1 more source