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Related papers: On uniqueness of characteristic classes

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Given a countable abelian group $A$, we construct a row finite directed graph $\Gamma(A)$ such that the $K_{0}$-group of the graph $\textrm{C}^{\ast}$-algebra $\textrm{C}^{\ast}(\Gamma(A))$ is canonically isomorphic to $A$. Moreover, each…

Operator Algebras · Mathematics 2025-12-23 Swarnendu Datta , Debashish Goswami , Soumalya Joardar

We discuss special properties of the spaces of characters and positive definite functions, as well as their associated dynamics, for arithmetic groups of product type. Axiomatizing these properties, we define the notions of charmenability…

Group Theory · Mathematics 2025-07-17 Uri Bader , Rémi Boutonnet , Cyril Houdayer , Jesse Peterson

We show that the characteristic polynomial and the Lefschetz zeta function are manifestations of the trace map from the $K$-theory of endomorphisms to topological restriction homology (TR). Along the way we generalize Lindenstrauss and…

Algebraic Topology · Mathematics 2020-06-15 Jonathan A. Campbell , John A. Lind , Cary Malkiewich , Kate Ponto , Inna Zakharevich

We define N-theory being some analogue of K-theory on the category of von Neumann algebras such that $K_0(A)\subset N_0(A)$ for any von Neumann algebra A. Moreover, it turns out to be possible to construct the extension of the Chern…

Operator Algebras · Mathematics 2007-05-23 A. A. Pavlov

We show a quantum version of Chern character homomorphism from the small quantum K-theory to the small quantum cohomology in the cases of projective spaces and incidence varieties, whose classical limit gives the classical Chern character…

Algebraic Geometry · Mathematics 2025-07-17 Hua-Zhong Ke , Changzheng Li , Jiayu Song

We show an analogue of Jordan's theorem for algebraic groups defined over a field $\mathbb k$ of arbitrary characteristic. As a consequence, a Jordan-type property holds for the automorphism group of any projective variety over $\mathbb k$.

Algebraic Geometry · Mathematics 2021-02-24 Fei Hu

Let $E$ be a $W^{\ast}$-correspondence over a von Neumann algebra $M$ and let $H^{\infty}(E)$ be the associated Hardy algebra. If $\sigma$ is a faithful normal representation of $M$ on a Hilbert space $H$, then one may form the dual…

Operator Algebras · Mathematics 2007-06-13 Paul S. Muhly , Baruch Solel

A theory of characteristic classes of vector bundles and smooth manifolds plays an important role in the theory of smooth manifolds. An investigation of reasonable notions of characteristic classes of singular spaces started since a…

Algebraic Geometry · Mathematics 2007-05-23 Joerg Schuermann , Shoji Yokura

We pose a conjecture on the K-theory of the self-similar $k$-graph C*-algebra of a standard product of odometers. We generalize the C*-algebra $\mathcal{Q}_S$ to any subset of $\mathbb{N}^\times \setminus \{1\}$ and then realize it as the…

Operator Algebras · Mathematics 2020-03-24 Hui Li

We show that the algebraic automorphism group of the SL(2,C) character variety of a closed orientable surface with negative Euler characteristic is a finite extension of its mapping class group. Along the way, we provide a simple…

Geometric Topology · Mathematics 2026-01-14 Julien Marché , Christopher-Lloyd Simon

The aim of this note is to define for any $e_n$-algebra $A$ and a compact parallelizable n-manifold $M$ without borders a morphism from the homology of homotopy Lie algebra $A[n-1]$ to the topological chiral homology of $M$ with…

Quantum Algebra · Mathematics 2013-04-25 Nikita Markarian

We introduce affine Stanley symmetric functions for the special orthogonal groups, a class of symmetric functions that model the cohomology of the affine Grassmannian, continuing the work of Lam and Lam, Schilling, and Shimozono on the…

Combinatorics · Mathematics 2011-11-15 Steven Pon

We consider a construction of C*-algebras from continuous piecewise monotone maps on the circle which generalizes the crossed product construction for homeomorphisms and more generally the construction of Renault, Deaconu and…

Operator Algebras · Mathematics 2019-02-20 Thomas L. Schmidt , Klaus Thomsen

In this article we construct explicit cocycles in the Alexander-Spanier cohomological complex, representing the Chern character of an element in K-theory.

K-Theory and Homology · Mathematics 2007-05-23 Alexander Gorokhovsky

Let $\Gamma$ be a finite graph and let $A(\Gamma)$ be the corresponding right-angled Artin group. We characterize the Hamiltonicity of $\Gamma$ via the structure of the cohomology algebra of $A(\Gamma)$. In doing so, we define and develop a…

Group Theory · Mathematics 2021-08-25 Ramón Flores , Delaram Kahrobaei , Thomas Koberda

Let $A$ be a finite-dimensional associative $k$-algebra with identity. The primary aim of this paper is to study the rationality properties of the group of all $k$-algebra automorphisms of $A$, as an affine algebraic group over an arbitrary…

Group Theory · Mathematics 2026-01-01 Dibyendu Das

We show that for a smooth, projective variety X defined over a number field K, cyclic homology with coefficients in the ring of infinite adeles of K, provides the right theory to obtain, using the lambda-operations, Serre's archimedean…

Algebraic Geometry · Mathematics 2012-11-20 Alain Connes , Caterina Consani

We revisit the construction of signature classes in C*-algebra K-theory, and develop a variation that allows us to prove equality of signature classes in some situations involving homotopy equivalences of noncompact manifolds that are only…

K-Theory and Homology · Mathematics 2018-10-03 Nigel Higson , Thomas Schick , Zhizhang Xie

Ram and Rammage have introduced an automorphism and Clifford theory on affine Hecke algebras. Here we will extend them to cyclotomic Hecke algebras and rational Cherednik algebras.

Representation Theory · Mathematics 2016-06-20 Shoumin Liu

In this paper, we construct and study derived character maps of finite-dimensional representations of $\infty$-groups. As models for $\infty$-groups we take homotopy simplicial groups, i.e. homotopy simplicial algebras over the algebraic…

Algebraic Topology · Mathematics 2025-01-01 Yuri Berest , Ajay C. Ramadoss