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Related papers: Classifying spaces of twisted loop groups

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We determine the mod $2$ cohomology over the Steenrod algebra of the classifying spaces of the free loop groups $LG$ for compact groups $G=Spin(7)$, $Spin(8)$, $Spin(9)$, and $F_4$. Then, we show that they are isomorphic as algebras over…

Algebraic Topology · Mathematics 2021-05-11 Shizuo Kaji

Consider the space Hom(Z^n,G) of pairwise commuting n-tuples of elements in a compact Lie group G. This forms a real algebraic variety, which is generally singular. In this paper, we construct a desingularization of the generic component of…

Algebraic Topology · Mathematics 2014-10-01 Thomas Baird

We study the space of conjugacy classes of subgroups of a compact Lie group G whose identity component is a torus, and consider how various invariants of subgroups behave as sheaves over this space. This feeds in to the author's programme…

Algebraic Topology · Mathematics 2025-10-20 J. P. C. Greenlees

Let G be a compact Lie-group, X a compact G-CW-complex. We define equivariant geometric K-homology groups K^G_*(X), using an obvious equivariant version of the (M,E,f)-picture of Baum-Douglas for K-homology. We define explicit natural…

K-Theory and Homology · Mathematics 2012-10-12 Paul Baum , Herve Oyono-Oyono , Thomas Schick , Michael Walter

Bergman has given the following abstract characterisation of the inner automorphisms of a group $G$: they are exactly those automorphisms of $G$ which can be extended functorially along any homomorphism $G \rightarrow H$ to an automorphism…

Category Theory · Mathematics 2019-07-25 Richard Garner

In this note we study topological invariants of the spaces of homomorphisms Hom(\pi,G), where \pi\ is a finitely generated abelian group and G is a compact Lie group arising as an arbitrary finite product of the classical groups SU(r), U(q)…

Algebraic Topology · Mathematics 2012-03-27 Alejandro Adem , José Manuel Gómez

We consider a problem on the conditions of a compact Lie group G that the loop space of the p-completed classifying space be a p-compact group for a set of primes. In particular, we discuss the classifying spaces BG that are p-compact for…

Algebraic Topology · Mathematics 2009-03-27 Kenshi Ishiguro

Let $G$ be a compact Lie group with a maximal torus $T$. Based on a presentation of the integral cohomology ring $H^{\ast}(G/T)$ of the flag manifold $G/T$ in \cite{DZ1}we have presented in \cite{DZ2}an explicit and unified construction of…

Algebraic Topology · Mathematics 2016-04-18 Haibao Duan

Continuing our previous work on graded twisting of Hopf algebras and monoidal categories, we introduce a graded twisting construction for equivariant comodule algebras and module categories. As an example we study actions of quantum…

Quantum Algebra · Mathematics 2021-06-09 Julien Bichon , Sergey Neshveyev , Makoto Yamashita

We show that for topological groups and loop contractible coefficients the cohomology groups of continuous group cochains and of group cochains that are continuous on some identity neighbourhood are isomorphic. Moreover, we show a similar…

Algebraic Topology · Mathematics 2013-02-14 Martin Fuchssteiner , Christoph Wockel

Let G be a connected complex simple Lie group with maximal compact subgroup U. Let g be the Lie algebra of G, and X = G/U be the associated Riemannian globally symmetric space of type IV. We have constructed three types of arithmetic…

Representation Theory · Mathematics 2019-12-23 Pampa Paul

We compute rationally the topological (complex) K-theory of the classifying space BG of a discrete group provided that G has a cocompact G-CW-model for its classifying space for proper G-actions. For instance word-hyperbolic groups and…

K-Theory and Homology · Mathematics 2007-05-23 Wolfgang Lueck

Let $\Gamma$ be a finite group acting on a Lie group $G$. We consider a class of group extensions $1 \to G \to \hat{G} \to \Gamma \to 1$ defined by this action and a $2$-cocycle of $\Gamma$ with values in the centre of $G$. We establish and…

Differential Geometry · Mathematics 2024-06-14 G. Barajas , O. García-Prada , P. B. Gothen , I. Mundet i Riera

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,…

K-Theory and Homology · Mathematics 2021-03-26 Tiberiu Coconet , Constantin-Cosmin Todea

We investigate analogues of some of the classical results in homogeneous dynamics in non-linear setting. Let $G$ be a closed subgroup of the group of automorphisms of a biregular tree and $\Gamma<G$ a discrete subgroup. For a large class of…

Dynamical Systems · Mathematics 2019-09-20 Corina Ciobotaru , Vladimir Finkelshtein , Cagri Sert

We define twisted equivariant K-homology groups using geometric cycles. We compare them with approaches using Kasparov KK-Theory and (twisted) group C*-algebras.

K-Theory and Homology · Mathematics 2015-01-27 Noe Barcenas

Let $G$ be a totally disconnected, locally compact group and let $H$ be a virtually flat (for example, polycyclic) group of automorphisms of $G$. We study the structure of, and relationships between, various subgroups of $G$ defined by the…

Group Theory · Mathematics 2016-02-15 Colin D. Reid

The equivariant cohomology of a space with a group action is not only a ring but also an algebra over the cohomology ring of the classifying space of the acting group. We prove that toric manifolds (i.e. compact smooth toric varieties) are…

Algebraic Topology · Mathematics 2008-11-28 Mikiya Masuda

The goal of the present paper is the calculation of the equivariant twisted K-theory of a compact Lie group which acts on itself by conjugations, and elements of a TQFT-structure on the twisted K-groups. These results are originally due to…

K-Theory and Homology · Mathematics 2007-05-23 Ulrich Bunke , Ingo Schroeder

Let PSigma_n denote the group that can be thought of either as the group of motions of the trivial n-component link or the group of symmetric automorphisms of a free group of rank n. The integral cohomology ring of PSigma_n is determined,…

Algebraic Topology · Mathematics 2009-03-03 Craig A Jensen , Jon McCammond , John Meier