Results 41 to 50 of about 12,457,095 (269)
A cocycle model for topological and Lie group cohomology [PDF]
We propose a unified framework in which the different constructions of cohomology groups for topological and Lie groups can all be treated on equal footings.
F. Wagemann, Christoph Wockel
semanticscholar +1 more source
Group cohomology with coefficients in a crossed module [PDF]
We compare three different ways of defining group cohomology with coefficients in a crossed module: (1) explicit approach via cocycles; (2) geometric approach via gerbes; (3) group theoretic approach via butterflies. We discuss the case where the crossed
B. Noohi
semanticscholar +1 more source
Symmetric cohomology of groups [PDF]
We investigate the relationship between the symmetric, exterior and classical cohomologies of groups. The first two theories were introduced respectively by Staic and Zarelua. We show in particular, that there is a map from exterior cohomology to symmetric cohomology which is a split monomorphism in general and an isomorphism in many cases, but not ...
openaire +5 more sources
On Schubert calculus in elliptic cohomology [PDF]
An important combinatorial result in equivariant cohomology and $K$-theory Schubert calculus is represented by the formulas of Billey and Graham-Willems for the localization of Schubert classes at torus fixed points.
Cristian Lenart, Kirill Zainoulline
doaj +1 more source
Productive elements in group cohomology [PDF]
Let $G$ be a finite group and $k$ be a field of characteristic $p>0$. A cohomology class $\zeta \in H^n(G,k)$ is called productive if it annihilates $\Ext^*_{kG}(L_{\zeta},L_{\zeta})$. We consider the chain complex $\bPz$ of projective $kG$-modules which
Ergün Yalçın
semanticscholar +1 more source
Let G be a group of Mobius transformations and V the space of com- plex polynomials of degree < some fixed even integer. Using the action of G on V defined by Eichler, we compute the dimension of the cohomology space H'(G, V), first for G an arbitrary F-group (a generalization of Fuchsian group) and then for the free product of finitely many F-groups ...
openaire +1 more source
The eleventh cohomology group of $\overline {\mathcal {M}}_{g,n}$
We prove that the rational cohomology group $H^{11}(\overline {\mathcal {M}}_{g,n})$ vanishes unless $g = 1$ and $n \geq 11$ . We show furthermore that $H^k(\overline {\mathcal {M}}_{g,n})$ is pure Hodge–Tate for all even ...
Samir Canning, Hannah Larson, Sam Payne
doaj +1 more source
Substitutions with Vanishing Rotationally Invariant First Cohomology
The cohomology groups of tiling spaces with three-fold and nine-fold symmetries are obtained. The substitution tilings are characterized by the fact that they have vanishing first cohomology group in the space of tilings modulo a rotation.
Juan García Escudero
doaj +1 more source
Generalized Bockstein maps and Massey products
Given a profinite group G of finite p-cohomological dimension and a pro-p quotient H of G by a closed normal subgroup N, we study the filtration on the Iwasawa cohomology of N by powers of the augmentation ideal in the group algebra of H.
Yeuk Hay Joshua Lam+4 more
doaj +1 more source
Symmetric Hochschild cohomology of twisted group algebras [PDF]
We show that there is an action of the symmetric group on the Hochschild cochain complex of a twisted group algebra with coefficients in a bimodule. This allows us to define the symmetric Hochschild cohomology of twisted group algebras, similarly to th construction of symmetric group cohomology due to Staic.
arxiv