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Related papers: A Note on Kasparov Product and Duality

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Answering a question of Carri\'on et al in their recent landmark paper on C*-algebra classification, we prove a general uniqueness theorem for $KK$-theory. Given arbitrary separable C*-algebras $A$ and $B$ and a Cuntz pair consisting of two…

Operator Algebras · Mathematics 2026-02-18 Gábor Szabó

Bott periodicity plays an important role in topological K-theory. The purpose of this paper is to extend the periodicity theorem in a discrete context, where all classical groups are involved and not just the general linear group. The…

K-Theory and Homology · Mathematics 2008-10-28 Max Karoubi

We prove a comparison result between two duality statements - Takai duality, which is implemented by the crossed product functor $- \rtimes G: KK^{G} \to KK^{\hat G}$ on equivariant Kasparov categories; and Treumann duality, which asserts…

K-Theory and Homology · Mathematics 2025-10-08 Vikram Nadig

In this paper, we introduce Kasparov's bivariant K-theory that is equivariant under symmetries of a C*-tensor category. It is motivated by some dualities in quantum group equivariant KK-theory, and the classification theory of inclusions of…

Operator Algebras · Mathematics 2025-03-19 Yuki Arano , Kan Kitamura , Yosuke Kubota

We construct a natural transformation between two versions of $G$-equivariant $K$-homology with coefficients in a $G$-$C^{*}$-category for a countable discrete group $G$. Its domain is a coarse geometric $K$-homology and its target is the…

Algebraic Topology · Mathematics 2025-12-10 Ulrich Bunke , Alexander Engel , Markus Land

Paschke duality identifies the K-homology of a space X with the K-theory of a certain dual C*-algebra. We show that Paschke's dual algebra is in a natural way the algebra of sections of a certain sheaf of C*-algebras over X, which can be…

K-Theory and Homology · Mathematics 2012-10-25 John Roe , Paul Siegel

We construct a slant product $\mathrm{S}^{G\times H}_p(X\times Y)\otimes \mathrm{K}_{-q}(\bar{\mathfrak{c}}^{\mathrm{red}} Y\rtimes H)\to \mathrm{K}_{p-q}(\mathrm{C}^\ast_G X)$ on the analytic structure group of Higson and Roe and the…

K-Theory and Homology · Mathematics 2025-06-17 Christopher Wulff , Rudolf Zeidler

Let $G$ be a compact connected Lie group and $K$ a closed connected subgroup. Assume that the order of any torsion element in the integral cohomology of $G$ and $K$ is invertible in a given principal ideal domain $k$. It is known that in…

Algebraic Topology · Mathematics 2021-11-24 Matthias Franz

We construct equivariant $KK$-theory with coefficients in $\mathbb{R}$ and $\mathbb{R}/\mathbb{Z}$ as suitable inductive limits over ${\rm II}_1$-factors. We show that the Kasparov product, together with its usual functorial properties,…

Operator Algebras · Mathematics 2015-04-20 Paolo Antonini , Sara Azzali , Georges Skandalis

We describe the index pairing between an odd K-theory class and an odd unbounded Kasparov module by a pair of quasi-projections, supported on a submodule obtained from a finite spectral truncation. We achieve this by pairing the K-theory…

K-Theory and Homology · Mathematics 2026-04-01 Yuezhao Li , Bram Mesland

We give a simple proof of the smooth Thom isomorphism for complex bundles for the bivariant K-theories on locally convex algebras considered by Cuntz. We also prove the Thom isomorphism in Kasparov's KK-theory in a form stated without proof…

K-Theory and Homology · Mathematics 2011-04-01 Martin Grensing

Suppose $A$ is a $C^*$-algebra and $H$ is a $C^*$-correspondence over $A$. If $H$ is regular in the sense that the left action of $A$ is faithful and is given by compact operators, then we compute the $K$-theory of $\mathcal{O}_A(H) \rtimes…

Operator Algebras · Mathematics 2015-03-03 Christopher Schafhauser

We give a detailed and unified survey of equivariant $KK$-theory over locally compact, second countable, locally Hausdorff groupoids. We indicate precisely how the "classical" proofs relating to the Kasparov product can be used almost…

K-Theory and Homology · Mathematics 2020-06-24 Lachlan MacDonald

We use homotopy theoretic ideas to study the $K$-theory of (graded, Real) $C^*$-algebras in detail. After laying the foundations, and deriving the formal properties, the comparison of the model with the Kasparov picture of $K$-theory has…

K-Theory and Homology · Mathematics 2024-10-30 Anupam Datta

We investigate an extension of ideas of Atiyah-Patodi-Singer (APS) to a noncommutative geometry setting framed in terms of Kasparov modules. We use a mapping cone construction to relate odd index pairings to even index pairings with APS…

K-Theory and Homology · Mathematics 2008-02-04 A. L. Carey , J. Phillips , A. Rennie

KK-theory is a bivariant and homotopy-invariant functor on $C^*$-algebras that combines K-theory and K-homology. KK-groups form the morphisms in a triangulated category. Spanier-Whitehead K-Duality intertwines the homological with the…

Operator Algebras · Mathematics 2026-01-08 Ulrich Pennig , Taro Sogabe

Using an appropriate notion of locally convex Kasparov modules, we show how to induce isomorphisms under a large class of functors on the category of locally convex algebras; examples are obtained from spectral triples. Our considerations…

K-Theory and Homology · Mathematics 2011-09-09 Martin Grensing

We consider topological insulators and superconductors with discrete symmetries and clarify the relevant index theory behind the periodic table proposed by Kitaev. An effective Hamiltonian determines the analytical index, which can be…

Mathematical Physics · Physics 2017-10-05 Dan Li

We define and study the index map for families of $G$-transversally elliptic operators and introduce the multiplicity for a given irreducible representation as a virtual bundle over the base of the fibration. We then prove the usual…

K-Theory and Homology · Mathematics 2019-04-24 Alexandre Baldare

Let the discrete group G act properly and isometrically on the Riemannian manifold X. Let C_0(X, \delta) be the section algebra of a smooth locally trivial G-equivariant bundle of elementary C*-algebras representing an element \delta of the…

Operator Algebras · Mathematics 2011-11-09 Siegfried Echterhoff , Heath Emerson , Hyun Jeong Kim
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