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Related papers: Talbot Workshop 2010 Talk 2: K-Theory and Index Th…

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We develop methods for computing graded K-theory of C*-algebras as defined in terms of Kasparov theory. We establish graded versions of Pimsner's six-term sequences for graded Hilbert bimodules whose left action is injective and by…

Operator Algebras · Mathematics 2017-06-05 Alex Kumjian , David Pask , Aidan Sims

Using semi-classical analysis in $\mathbb{R}^{n}$ we present a quite general model for which the topological index formula of Atiyah-Singer predicts a spectral flow with the transition of a finite number of eigenvalues between clusters…

Mathematical Physics · Physics 2023-09-26 Frédéric Faure

We develop elliptic theory of operators associated with a diffeomorphism of a closed smooth manifold. The aim of the present paper is to obtain an index formula for such operators in terms of topological invariants of the manifold and of…

Operator Algebras · Mathematics 2015-11-06 Anton Savin , Boris Sternin

In a previous paper we have introduced the gauge-equivariant K-theory group of a bundle endowed with a continuous action of a bundle of compact Lie groups. These groups are the natural range for the analytic index of a family of…

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

The Farrell-Jones and the Baum-Connes Conjecture say that one can compute the algebraic K- and L-theory of the group ring and the topological K-theory of the reduced group C^*-algebra of a group G in terms of these functors for the…

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

Index maps taking values in the $K$-theory of a mapping cone are defined and discussed. The resulting index theorem can be viewed in analogy with the Freed-Melrose index theorem. The framework of geometric $K$-homology is used in a…

K-Theory and Homology · Mathematics 2016-03-11 Robin J. Deeley

The construction of twisted K-theory classes on a compact Lie group is reviewed using the supersymmetric Wess-Zumino-Witten model on a cylinder. The Quillen superconnection is introduced for a family of supercharges and the Chern character…

High Energy Physics - Theory · Physics 2007-05-23 Jouko Mickelsson

This paper gives insight into intriguing connections between two apparently unrelated theories: the theory of skein modules of 3-manifolds and the theory of representations of groups into special linear groups of 2 by 2 matrices. Let R be a…

q-alg · Mathematics 2008-02-03 Jozef H. Przytycki , Adam S. Sikora

In this paper, we develop twisted $K$-theory for stacks, where the twisted class is given by an $S^1$-gerbe over the stack. General properties, including the Mayer-Vietoris property, Bott periodicity, and the product structure $K^i_\alpha…

K-Theory and Homology · Mathematics 2007-05-23 Jean-Louis Tu , Ping Xu , Camille Laurent-Gengoux

For a space X acted by a finite group $\G$, the product space $X^n$ affords a natural action of the wreath product $\Gn$. In this paper we study the K-groups $K_{\tG_n}(X^n)$ of $\Gn$-equivariant Clifford supermodules on $X^n$. We show that…

Quantum Algebra · Mathematics 2009-11-07 Weiqiang Wang

We describe a special class of representations of an inverse semigroup S on Hilbert's space which we term "tight". These representations are supported on a subset of the spectrum of the idempotent semilattice of S, called the "tight…

Operator Algebras · Mathematics 2008-06-25 Ruy Exel

It seems that the index theory for non-compact spaces has found its ultimate formulation in realm of coarse spaces and $K$-theory of related operator algebras. Relative and partitioned index theorems may be mentioned as two important and…

K-Theory and Homology · Mathematics 2018-04-03 Moin Karami , Mostafa E. Zadeh , Ahmad H. S. Sadegh

We continue the study of the effective content of $K$-theory for C*-algebras, with a focus on AF algebras. We show that from a c.e. presentation of an AF algebra it is possible to compute a representation of the algebra as an inductive…

Operator Algebras · Mathematics 2026-02-09 Christopher J. Eagle , Isaac Goldbring , Timothy H. McNicholl

We develop a categorical index calculus for elliptic symbol families. The categorified index problems we consider are a secondary version of the traditional problem of expressing the index class in K-theory in terms of…

Differential Geometry · Mathematics 2019-01-31 Markus Upmeier

We provide a general formula for the partition function of three-dimensional $\mathcal{N}=2$ gauge theories placed on $S^2 \times S^1$ with a topological twist along $S^2$, which can be interpreted as an index for chiral states of the…

High Energy Physics - Theory · Physics 2015-10-29 Francesco Benini , Alberto Zaffaroni

We derive formulas and algorithms for Kitaev's invariants in the periodic table for topological insulators and superconductors for finite disordered systems on lattices with boundaries. We find that K-theory arises as an obstruction to…

Mesoscale and Nanoscale Physics · Physics 2015-08-11 Terry A. Loring

In this talk, we review the heat kernel approach to the Atiyah-Singer index theorem for Dirac operators on closed manifolds, as well as the Atiyah-Patodi-Singer index theorem for Dirac operators on manifolds with boundary. We also discuss…

Differential Geometry · Mathematics 2016-09-07 Weiping Zhang

Genus one amplitude for topological strings on Calabi-Yau 3-folds can be computed using mirror symmetry: The partition function at genus one gets mapped to a holomorphic version of Ray-Singer torsion on the mirror Calabi-Yau. On the other…

High Energy Physics - Theory · Physics 2024-03-12 Cumrun Vafa

Representations of Spin groups and Clifford algebras derived from the structure of qubit trees are introduced in this work. For ternary trees the construction is more general and reduction to binary trees is formally defined by deletion of…

Quantum Physics · Physics 2022-12-06 Alexander Yu. Vlasov

Let $\Scr A$ be a unital C*-algebra. We describe \it K-skeleton factorizations \rm of all invertible operators on a Hilbert C*-module $\Scr H_{\Scr A}$, in particular on $\Scr H=l^2$, with the Fredholm index as an invariant. We then outline…

Operator Algebras · Mathematics 2009-09-25 Shuang Zhang
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