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Related papers: Algebraic K-theory and trace invariants

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This paper is comprised of two related parts. First we discuss which k-graph algebras have faithful gauge invariant traces, where the gauge action of $\T^k$ is the canonical one. We give a sufficient condition for the existence of such a…

Operator Algebras · Mathematics 2007-05-23 David Pask , Adam Rennie , Aidan Sims

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 a twisted version of $K$-theory with coefficients in a $C^*$-algebra $A$, where the twist is given by a new kind of gerbe, which we call Morita bundle gerbe. We use the description of twisted $K$-theory in the torsion case by…

K-Theory and Homology · Mathematics 2011-03-22 Ulrich Pennig

Let $K$ be a complete discrete valuation field with finite residue field of characteristic $p$, and let $D$ be a central division algebra over $K$ of finite index $d$. Thirty years ago, Suslin and Yufryakov showed that for all prime numbers…

K-Theory and Homology · Mathematics 2019-08-06 Lars Hesselholt , Michael Larsen , Ayelet Lindenstrauss

Equivariant homotopy methods developed over the last 20 years lead to recent breakthroughs in the Borel isomorphism conjectures for Loday assembly maps in K- and L-theories. An important consequence of these algebraic conjectures is the…

Algebraic Topology · Mathematics 2019-06-25 Gunnar Carlsson , Boris Goldfarb

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

In an earlier paper, the authors introduced partial translation algebras as a generalisation of group C*-algebras. Here we establish an extension of partial translation algebras, which may be viewed as an excision theorem in this context.…

Operator Algebras · Mathematics 2013-04-29 Jacek Brodzki , Graham A. Niblo , Nick Wright

We show that if $X$ is a toric scheme over a regular commutative ring $k$ then the direct limit of the $K$-groups of $X$ taken over any infinite sequence of nontrivial dilations is homotopy invariant. This theorem was previously known for…

K-Theory and Homology · Mathematics 2017-03-24 Guillermo Cortiñas , Christian Haesemeyer , Mark E. Walker , Charles Weibel

Let $X$ be a toric $\mbox{hyperK\"ahler}$ manifold. The purpose of this note is to describe the topological $K$-ring $K^*(X)$ of $X$. We give a presentation for the topological $K$-ring in terms of generators and relations similar to the…

Algebraic Topology · Mathematics 2018-08-10 V. Uma

We construct a sequence of $n-1$ cyclic exact sequences that can be used to compute the $K$-theory of the $C^\star$-algebra crossed product $A \ltimes {\mathbb Z}_n$.

Operator Algebras · Mathematics 2015-05-11 Larry B. Schweitzer

This paper seeks to characterize some topological properties of pro-countable abelian topological groups. Using the Milnor exact sequence given by the controlled picture of $KK$-theory by Willett and Yu, we describe topological properties…

K-Theory and Homology · Mathematics 2025-11-19 Arturo Jaime

This is a survey on the topic explained in the title, for the proceedings on the K-theory 1997 summer institute in Seattle.

Algebraic Geometry · Mathematics 2007-05-23 Hélène Esnault

We extend the stable motivic homotopy category of Voevodsky to the class of scalloped algebraic stacks, and show that it admits the formalism of Grothendieck's six operations. Objects in this category represent generalized cohomology…

Algebraic Geometry · Mathematics 2024-10-10 Adeel A. Khan , Charanya Ravi

We unite elements of category theory, K-theory, and geometric group theory, by defining a class of groups called $k$-cube groups, which act freely and transitively on the product of $k$ trees, for arbitrary $k$. The quotient of this action…

Operator Algebras · Mathematics 2024-01-12 Sam A. Mutter , Aura-Cristiana Radu , Alina Vdovina

We consider a connected compact Lie group K acting on a symplectic manifold M such that a moment map m exists. A pull-back function via m Poisson commutes with all K-invariants. Guillemin-Sternberg raised the problem to find a converse. In…

dg-ga · Mathematics 2007-05-23 Friedrich Knop

This paper constitutes a first step in the author's program to investigate the question of when a homotopy of 2-cocycles $\omega = \{\omega_t\}_{t \in [0,1]}$ on a locally compact Hausdorff groupoid $\mathcal{G}$ induces an isomorphism of…

Operator Algebras · Mathematics 2014-09-09 Elizabeth Gillaspy

We extend Geisser and Hesselholt's result on ``bi-relative K-theory'' from discrete rings to connective ring spectra. That is, if $\mathcal A$ is a homotopy cartesian $n$-cube of ring spectra (satisfying connectivity hypotheses), then the…

K-Theory and Homology · Mathematics 2007-05-23 Bjørn Ian Dundas , Harald Øyen Kittang

I conjecture that index formulas for $K$-theory classes on the moduli of holomorphic $G$-bundles over a compact Riemann surface $\Sigma$ are controlled, in a precise way, by Frobenius algebra deformations of the Verlinde algebra of $G$. The…

Algebraic Geometry · Mathematics 2007-05-23 Constantin Teleman

We give complete descriptions of the tracial states on both the universal and reduced crossed products of a C*-dynamical system consisting of a unital C*-algebra and a discrete group. In particular, we also answer the question of when the…

Operator Algebras · Mathematics 2021-08-19 Dan Ursu

The deep interconnection between linear algebra and graph theory allows one to interpret classical matrix invariants through combinatorial structures. To each square matrix A over a commutative ring K, one can associate a weighted directed…

Combinatorics · Mathematics 2025-11-11 Sudip Bera