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Related papers: K-theory and elliptic operators

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We define the gauge-equivariant index of a family of elliptic operators invariant with respect to the free action of a family $\GR \to B$ of Lie groups (these families are called ``gauge-invariant families'' in what follows). If the fibers…

K-Theory and Homology · Mathematics 2007-05-23 Victor Nistor

The Chern classes of a K-theory class which is represented by a vector bundle with connection admit refinements to Cheeger-Simons classes in Deligne cohomology. In the present paper we consider similar refinements in the case where the…

Differential Geometry · Mathematics 2007-05-23 U. Bunke

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

In previous papers (arxiv:math/0612370 and arxiv:0909.1342) we defined the C*-algebra and the longitudinal pseudodifferential calculus of any singular foliation (M,F). Here we construct the analytic index of an elliptic operator as a…

Operator Algebras · Mathematics 2010-05-03 Iakovos Androulidakis , Georges Skandalis

We compare two approaches which use K-theory for C*-algebras to classify symmetry protected topological phases of quantum systems described in the one particle approximation. In the approach by Kellendonk, which is more abstract and more…

Operator Algebras · Mathematics 2025-12-02 Scaglione Lorenzo

We define an analytic index and prove a topological index theorem for a non-compact manifold $M\_0$ with poly-cylindrical ends. We prove that an elliptic operator $P$ on $M\_0$ has an invertible perturbation $P+R$ by a lower order operator…

K-Theory and Homology · Mathematics 2019-02-20 Bertrand Monthubert , Victor Nistor

Using the unbounded picture of analytical K-homology, we associate a well-defined K-homology class to an unbounded symmetric operator satisfying certain mild technical conditions. We also establish an ``addition formula'' for the Dirac…

K-Theory and Homology · Mathematics 2007-05-23 Hela Bettaieb , Michel Matthey , Alain Valette

The principal result of this note is the existence of a complex topological orientation for Atiyah-Segal $\mathbb{T}$-equivariant K-theory which indexes the projective space of lines in complex (n+1)-space by the Fourier expansion $1 + q +…

K-Theory and Homology · Mathematics 2025-06-19 J Morava

We show how methods from K-theory of operator algebras can be applied in a completely algebraic setting to define a bivariant, matrix-stable, homotopy-invariant, excisive K-theory of algebras over a fixed unital ground ring H, kk_*(A,B),…

K-Theory and Homology · Mathematics 2011-08-03 Guillermo Cortiñas , Andreas Thom

The twisted equivariant K-theory given by Freed and Moore is a K-theory which unifies twisted equivariant complex K-theory, Atiyah's `Real' K-theory, and their variants. In a general setting, we formulate this K-theory by using Fredholm…

K-Theory and Homology · Mathematics 2021-02-23 Kiyonori Gomi

Let G be a compact connected Lie group, and (M,\omega) a Hamiltonian G-space with proper moment map \mu. We give a surjectivity result which expresses the K-theory of the symplectic quotient M//G in terms of the equivariant K-theory of the…

Symplectic Geometry · Mathematics 2007-05-23 Megumi Harada , Gregory D. Landweber

We construct the Schubert basis of the torus-equivariant K-homology of the affine Grassmannian of a simple algebraic group G, using the K-theoretic NilHecke ring of Kostant and Kumar. This is the K-theoretic analogue of a construction of…

Combinatorics · Mathematics 2019-02-20 Thomas Lam , Anne Schilling , Mark Shimozono

These lecture notes contain an exposition of basic ideas of K-theory and cyclic cohomology. I begin with a list of examples of various situations in which the K-functor of Grothendieck appears naturally, including the rudiments of the…

funct-an · Mathematics 2008-02-03 Jacek Brodzki

We consider generalised Dirac--Schr\"odinger operators, consisting of a self-adjoint elliptic first-order differential operator D with a skew-adjoint 'potential' given by a (suitable) family of unbounded operators. The index of such an…

K-Theory and Homology · Mathematics 2025-01-29 Koen van den Dungen

We establish an index theorem for Toeplitz operators on odd dimensional spin manifolds with boundary. It may be thought of as an odd dimensional analogue of the Atiyah-Patodi-Singer index theorem for Dirac operators on manifolds with…

Differential Geometry · Mathematics 2007-05-23 Xianzhe Dai , Weiping Zhang

Let M be a compact manifold with a fixed spin structure \chi. The Atiyah-Singer index theorem implies that for any metric g on M the dimension of the kernel of the Dirac operator is bounded from below by a topological quantity depending…

Differential Geometry · Mathematics 2011-07-21 Bernd Ammann , Mattias Dahl , Emmanuel Humbert

This is an appendix to the paper {\bf Asymptotic K-theory for groups acting on $\tA_2$ buildings}, and contains the results of the computations performed by the authors.

Operator Algebras · Mathematics 2007-05-23 Guyan Robertson , Tim Steger

A group action on the input ring or category induces an action on the algebraic $K$-theory spectrum. However, a shortcoming of this naive approach to equivariant algebraic $K$-theory is, for example, that the map of spectra with $G$-action…

Algebraic Topology · Mathematics 2016-09-14 Mona Merling

Let T be a compact torus and (M,\omega) a Hamiltonian T-space. In a previous paper, the authors showed that the T-equivariant K-theory of the manifold M surjects onto the ordinary integral K-theory of the symplectic quotient M \mod T of M…

Symplectic Geometry · Mathematics 2008-01-02 Megumi Harada , Gregory D. Landweber

We introduce and study the index morphism for G-invariant leafwise G-transversally elliptic operators on smooth closed foliated manifolds which are endowed with leafwise actions of the compact group G. We prove the usual axioms of excision,…

K-Theory and Homology · Mathematics 2021-03-17 Alexandre Baldare , Moulay-Tahar Benameur