English
Related papers

Related papers: Twisted K-theory and finite-dimensional approximat…

200 papers

Let U be the group of units of an infinite twisted group algebra K_\lambda G over a field K. We describe the maximal FC-subgroup of U and give a characterization of U with finitely conjugacy classes. In the case of group algebras we obtain…

Rings and Algebras · Mathematics 2008-03-19 Victor Bovdi

We prove `twisted' versions of Kirchhoff's network theorem and Kirchhoff's matrix-tree theorem on connected finite graphs. Twisting here refers to chains with coefficients in a flat unitary line bundle.

Algebraic Topology · Mathematics 2013-06-11 Michael J. Catanzaro , Vladimir Y. Chernyak , John R. Klein

We construct and study a bicategory of super 2-line bundles over graded Lie groupoids, providing a unified framework for geometric models of twistings of (Real) K-theory. The core of our work is to exhibit a wide range of models from the…

Algebraic Topology · Mathematics 2025-02-26 Tim Lüders , Lynn Otto , Konrad Waldorf

We introduce a periodic form of the iterated algebraic K-theory of ku, the (connective) complex K-theory spectrum, as well as a natural twisting of this cohomology theory by higher gerbes. Furthermore, we prove a form of topological…

Algebraic Topology · Mathematics 2020-03-25 John A. Lind , Hisham Sati , Craig Westerland

We develop a operator algebraic model for twisted $K$-theory, which includes the most general twistings as a generalized cohomology theory (i.e. all those classified by the unit spectrum $bgl_1(KU)$). Our model is based on strongly…

K-Theory and Homology · Mathematics 2016-03-07 Ulrich Pennig

In this paper, we recall the definition of twisted K-theory in various settings. We prove that for a twist $\tau$ corresponding to a three dimensional integral cohomology class of a space X, there exist a "universal coefficient" isomorphism…

Algebraic Topology · Mathematics 2014-02-26 Mehdi Khorami

We define equivariant projective unitary stable bundles as the appropriate twists when defining K-theory as sections of bundles with fibers the space of Fredholm operators over a Hilbert space. We construct universal equivariant projective…

Algebraic Topology · Mathematics 2018-05-16 Noe Barcenas , Jesus Espinoza , Michael Joachim , Bernardo Uribe

We discuss twisted cohomology, not just for ordinary cohomology but also for $K$-theory and other exceptional cohomology theories, and discuss several of the applications of these in mathematical physics. Our list of applications is by no…

Algebraic Topology · Mathematics 2024-01-09 Jonathan Rosenberg

This paper sets out basic properties of motivic twisted K-theory with respect to degree three motivic cohomology classes of weight one. Motivic twisted K-theory is defined in terms of such motivic cohomology classes by taking pullbacks…

Algebraic Topology · Mathematics 2010-08-31 Markus Spitzweck , Paul Arne Østvær

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

This is the third paper of a series relating the equivariant twisted $K$-theory of a compact Lie group $G$ to the ``Verlinde space'' of isomorphism classes of projective lowest-weight representations of the loop groups. Here, we treat…

Algebraic Topology · Mathematics 2007-05-23 Daniel S. Freed , Michael J. Hopkins , Constantin Teleman

Almost flat finitely generated projective Hilbert C*-module bundles were successfully used by Hanke and Schick to prove special cases of the Strong Novikov Conjecture. Dadarlat later showed that it is possible to calculate the index of a…

Differential Geometry · Mathematics 2021-05-25 Benedikt Hunger

We show how general principles of symmetry in quantum mechanics lead to twisted notions of a group representation. This framework generalizes both the classical 3-fold way of real/complex/quaternionic representations as well as a…

High Energy Physics - Theory · Physics 2015-06-11 Daniel S. Freed , Gregory W. Moore

We investigate how one can twist L^2-invariants such as L^2-Betti numbers and L^2-torsion with finite-dimensional representations. As a special case we assign to the universal covering of a finite connected CW-complex X together with an…

Geometric Topology · Mathematics 2017-03-28 Wolfgang Lueck

We classify the irreducible finite-dimensional representations of the twisted quantum affine algebras.

q-alg · Mathematics 2008-02-03 Vyjayanthi Chari , Andrew Pressley

B-fields over a groupoid with involution are defined as Real graded Dixmier-Douady bundles. We use these to introduce the Real graded Brauer group which constitutes the set of twistings for Atiyah's KR-functor in the category of locally…

K-Theory and Homology · Mathematics 2011-11-01 El-kaïoum M. Moutuou

Let $K$ be a finite group and let $G$ be a finite group acting on $K$ by automorphisms. In this paper we study two different but intimately related subjects: on the one side we classify all possible multiplicative and associative structures…

Quantum Algebra · Mathematics 2021-03-08 César Galindo , Ismael Gutiérrez , Bernardo Uribe

Motivated by classical facts concerning closed manifolds, we introduce a strong finiteness property in K-homology. We say that a C*-algebra has uniformly summable K-homology if all its K-homology classes can be represented by Fredholm…

Operator Algebras · Mathematics 2015-12-16 Heath Emerson , Bogdan Nica

We introduce twisted K-theoretic Gromov-Witten invariants - in the frameworks of both "ordinary" and permutation-equivariant K-theoretic GW theory defined recently by Givental. We focus on the case when the twisting is given by the Euler…

Algebraic Geometry · Mathematics 2016-06-03 Valentin Tonita

Twisted K-theory has received much attention recently in both mathematics and physics. We describe some models of twisted K-theory, both topological and geometric. Then we state a theorem which relates representations of loop groups to…

Algebraic Topology · Mathematics 2007-05-23 Daniel S. Freed