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Related papers: Retraction of the bivariant Chern character

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The Chern-Dold character of a cohomology theory E is a canonical transformation $E\rightarrow HV$ to ordinary cohomology. A spectrum representing E gives homotopy theoretic cocycles for E, while HV can be represented by singular cocycles.…

Algebraic Topology · Mathematics 2014-04-09 Markus Upmeier

We show that the universal odd Chern form, defined on the stable unitary group $U$, extends to the loop group $LU$ in a way that is closed with respect to an equivariant-type differential. This provides an odd analogue to the Bismut-Chern…

Algebraic Topology · Mathematics 2013-11-27 Scott O. Wilson

If I is a nilpotent ideal in a $\mathbb{Q}$-algebra $A$, Goodwillie defined two isomorphisms from $K_*(A,I)$ to negative cyclic homology, $HN_*(A,I)$. One is the relative version of the absolute Chern character, and the other is defined…

K-Theory and Homology · Mathematics 2011-08-03 Guillermo Cortiñas , Charles Weibel

We construct a Hochschild-Kostant-Rosenberg-type quasi-isomorphism for the negative cyclic homology of the category of global matrix factorizations on a smooth separated scheme of finite type over a field. The map is explicit enough to…

Algebraic Geometry · Mathematics 2021-09-30 Kuerak Chung , Bumsig Kim , Taejung Kim

We examine Hopf cyclic cohomology in the same context as the analysis of the geometry of loop spaces $LX$ in derived algebraic geometry and the resulting close relationship between $S^1$-equivariant quasi-coherent sheaves on $LX$ and…

K-Theory and Homology · Mathematics 2019-04-09 Ilya Shapiro

In this paper we compute the K-theory (algebraic and topological) and entire periodic cyclic homology for compact quantum groups, define Chern characters between them and show that the Chern characters in both topological and algebraic…

Quantum Algebra · Mathematics 2014-06-09 Do Ngoc Diep , Aderemi O. Kuku , Nguyen Quoc Tho

Notes for some talks given at the seminar on characteristic classes at NTNU in autumn 2006. In the paper a proof of the existence of a Chern-character from complex K-theory to any cohomology theory with values in graded Q-algebras is given.…

Algebraic Geometry · Mathematics 2020-11-13 Helge Øystein Maakestad

Connes and Cuntz showed in [Comm. Math. Phys. 114 (1988), 515-526] that suitable cyclic cocycles can be represented as Chern characters of finitely summable semifinite Fredholm modules. We show an analogous result in twisted cyclic…

K-Theory and Homology · Mathematics 2013-08-01 Adam Rennie , Andrzej Sitarz , Makoto Yamashita

Given a C$^*$-dynamical system $(A, G, \alpha)$ one defines a homomorphism, called the Chern-Connes character, that take an element in $K_0(A) \oplus K_1(A)$, the K-theory groups of the C$^*$-algebra $A$, and maps it into…

Operator Algebras · Mathematics 2008-08-06 David P. Dias

We construct for an equivariant cohomology theory for proper equivariant CW-complexes an equivariant Chern character, provided that certain conditions about the coefficients are satisfied. These conditions are fulfilled if the coefficients…

Geometric Topology · Mathematics 2007-05-23 Wolfgang Lueck

We use some BRS techniques to construct Chern-Simons forms generalizing the Chern character of K_1 groups in the Cuntz-Quillen description of cyclic homology.

High Energy Physics - Theory · Physics 2007-05-23 Denis Perrot

In this paper we consider a family of Dirac-type operators on fibration $P \to B$ equivariant with respect to an action of an etale groupoid. Such a family defines an element in the bivariant $K$ theory. We compute the action of the…

Differential Geometry · Mathematics 2007-05-23 Alexander Gorokhovsky

For a finite group G acting on a smooth projective variety X, we construct two new G-equivariant rings: first the stringy K-theory of X, and second the stringy cohomology of X. For a smooth Deligne-Mumford stack Y we also construct a new…

Algebraic Geometry · Mathematics 2009-11-11 Tyler J. Jarvis , Ralph Kaufmann , Takashi Kimura

In this paper, we study the Chern character operators on the equivariant cohomology of the Hilbert schemes of points in the complex affine plane $C^2$ with the action of the torus $(C^*)^2$, and partially verify Okounkov's Conjecture [Oko,…

Algebraic Geometry · Mathematics 2025-05-21 Mazen M. Alhwaimel , Zhenbo Qin

We view the space of cotraces in the structural coalgebra of a principal coaction as a noncommutative counterpart of the classical Cartan model. Then we define the cyclic-homology Chern-Weil homomorphism by extending the Chern-Galois…

K-Theory and Homology · Mathematics 2017-12-29 Piotr M. Hajac , Tomasz Maszczyk

Given a smooth action of a Lie group on a manifold, we give two constructions of the Chern character of an equivariant vector bundle in the cyclic cohomology of the crossed product algebra. The first construction associates a cycle to the…

Differential Geometry · Mathematics 2023-04-10 Bjarne Kosmeijer , Hessel Posthuma

The treatment of supersymmetry is known to cause difficulties in the C*-algebraic framework of relativistic quantum field theory; several no-go theorems indicate that super-derivations and super-KMS functionals must be quite singular…

Mathematical Physics · Physics 2008-11-26 Detlev Buchholz , Hendrik Grundling

We introduce the notion of a {\vartheta}-summable Fredholm module over a locally convex dg algebra {\Omega} and construct its Chern character as a cocycle on the entire cyclic complex of {\Omega}, extending the construction of Jaffe,…

K-Theory and Homology · Mathematics 2021-03-15 Batu Güneysu , Matthias Ludewig

The purpose of this work is to give a definition of a topological K-theory for dg-categories over C and to prove that the Chern character map from algebraic K-theory to periodic cyclic homology descends naturally to this new invariant. This…

K-Theory and Homology · Mathematics 2019-02-20 Anthony Blanc

The purpose of this work is to provide details about the construction of the Chern character for categorical sheaves mentioned in our previous work "Chern character, loop spaces and derived algebraic geometry". For this, we introduce and…

Algebraic Geometry · Mathematics 2011-02-15 B. Toen , G. Vezzosi