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Related papers: Equivariant $KK$-theory and model categories

200 papers

We generalize several comparison results between algebraic, semi-topological and topological K-theories to the equivariant case with respect to a finite group.

K-Theory and Homology · Mathematics 2013-08-21 Jeremiah Heller , Jens Hornbostel

Kasparov $KK$-groups $KK(A,B)$ are represented as homotopy groups of the Pedersen-Weibel nonconnective algebraic $K$-theory spectrum of the additive category of Fredholm $(A,B)$-bimodules for $A$ and $B$, respectively, a separable and…

K-Theory and Homology · Mathematics 2007-05-23 Tamaz Kandelaki

In the present paper we introduce and study the notion of an equivariant pretheory: basic examples include equivariant Chow groups, equivariant K-theory and equivariant algebraic cobordism. To extend this set of examples we define an…

Algebraic Geometry · Mathematics 2013-02-07 Stefan Gille , Kirill Zainoulline

In this paper we identify QD(A,B), the quasidiagonal classes in KK_1(A,B), in terms of K_*(A) and K_*(B), and we use these results in various applications. Here is our central result. Theorem: Suppose that A is in the category of separable…

Operator Algebras · Mathematics 2007-05-23 Claude Schochet

We prove some fundamental results like localization, excision, Nisnevich descent and the Mayer-Vietoris property for equivariant regular blow-up for the equivariant K-theory of schemes with an affine group scheme action. We also show that…

Algebraic Geometry · Mathematics 2017-08-03 Amalendu Krishna , Charanya Ravi

We introduce and compare two approaches to equivariant homotopy theory in a topological or ordinary Quillen model category. For the topological model category of spaces, we generalize Piacenza's result that the categories of topological…

Algebraic Topology · Mathematics 2017-03-06 Marc Stephan

For an $r$-discrete Hausdorff groupoid ${\cal G}$ and an inverse semigroup $S$ of slices of ${\cal G}$ there is an isomorphism between ${\cal G}$-equivariant $KK$-theory and compatible $S$-equivariant $KK$-theory. We use it to define…

K-Theory and Homology · Mathematics 2012-11-22 Bernhard Burgstaller

We generalize a recent result of Clausen: For a number field with integers O, we compute the K-theory of locally compact O-modules. For the rational integers this recovers Clausen's result as a special case. Our method of proof is quite…

K-Theory and Homology · Mathematics 2017-10-31 Oliver Braunling

We redefine the Baum-Connes assembly map using simplicial approximation in the equivariant Kasparov category. This new interpretation is ideal for studying functorial properties and gives analogues of the assembly maps for all equivariant…

K-Theory and Homology · Mathematics 2015-10-23 Ralf Meyer , Ryszard Nest

We present some results on equivariant KK-theory in the context of tensor triangular geometry. More specifically, for G a finite group, we show that the spectrum of the tensor triangulated subcategory of KK^G generated by the tensor unit…

K-Theory and Homology · Mathematics 2011-01-13 Ivo Dell'Ambrogio

In this article we describe the $G\times G$-equivariant $K$-ring of $X$, where $X$ is a regular compactification of a connected complex reductive algebraic group $G$. Furthermore, in the case when $G$ is a semisimple group of adjoint type,…

Algebraic Geometry · Mathematics 2007-06-12 V. Uma

We establish axiomatic characterizations of $K$-theory and $KK$-theory for real C*-algebras. In particular, let $F$ be an abelian group-valued functor on separable real C*-algebras. We prove that if $F$ is homotopy invariant, stable, and…

Operator Algebras · Mathematics 2012-10-15 Jeffrey L. Boersema , Efren Ruiz

We state a precise conjectural isomorphism between localizations of the equivariant quantum K-theory ring of a flag variety and the equivariant K-homology ring of the affine Grassmannian, in particular relating their Schubert bases and…

Algebraic Geometry · Mathematics 2017-05-10 Thomas Lam , Changzheng Li , Leonardo C. Mihalcea , Mark Shimozono

We prove a formula for the structure constants of multiplication of equivariant Schubert classes in both equivariant cohomology and equivariant K-theory of Kac-Moody flag manifolds G/B. We introduce new operators whose coefficients compute…

Algebraic Geometry · Mathematics 2021-09-16 Rebecca Goldin , Allen Knutson

We describe the equivariant K-groups of a family of generalized Steinberg varieties that interpolates between the Steinberg variety of a reductive, complex algebraic group and its nilpotent cone in terms of the extended affine Hecke algebra…

Representation Theory · Mathematics 2013-11-26 J. Matthew Douglass , Gerhard Roehrle

A duality is discussed for Lie group bundles vs. certain tensor categories with non-simple identity, in the setting of Nistor-Troitsky gauge-equivariant K-theory. As an application, we study C*-algebra bundles with fibre a fixed-point…

K-Theory and Homology · Mathematics 2007-12-03 Ezio Vasselli

Following Hopkins and Singer, we give a definition for the differential equivariant K-theory of a smooth manifold acted upon by a finite group. The ring structure for differential equivariant K-theory is developed explicitly. We also…

Algebraic Topology · Mathematics 2009-06-01 Michael L. Ortiz

We obtain a formula for structure constants of certain variant form of Bott-Samelson classes for equivariant oriented cohomology of flag varieties. Specializing to singular cohomology/K-theory, we recover formulas of structure constants of…

Algebraic Geometry · Mathematics 2024-04-15 Rebecca Goldin , Changlong Zhong

Let $\Uq$ be a quantum group. Regarding a (noncommutative) space with $\Uq$-symmetry as a $\Uq$-module algebra $A$, we may think of equivariant vector bundles on $A$ as projective $A$-modules with compatible $\Uq$-action. We construct an…

Quantum Algebra · Mathematics 2009-12-21 G. I. Lehrer , R. B. Zhang

This is a survey article with the goal to advertise spectrum valued versions of $K$- and $KK$- theory for $C^{*}$-algebras via a (stable and symmetric monoidal) $\infty$-categorical enhancement of Kasparov's classical $KK$-theory. The main…

Operator Algebras · Mathematics 2023-11-30 Ulrich Bunke , Markus Land , Ulrich Pennig