English
Related papers

Related papers: Noncommutative stable homotopy theory

200 papers

We establish the stable homotopy classification of elliptic pseudodifferential operators on manifolds with corners and show that the set of elliptic operators modulo stable homotopy is isomorphic to the K-homology group of some stratified…

K-Theory and Homology · Mathematics 2007-05-23 V. E. Nazaikinskii , A. Yu. Savin , B. Yu. Sternin

Commutative $d$-torsion $K$-theory is a variant of topological $K$-theory constructed from commuting unitary matrices of order dividing $d$. Such matrices appear as solutions of linear constraint systems that play a role in the study of…

Algebraic Topology · Mathematics 2024-06-19 Cihan Okay

The ain of this note is to make available the unpublished proof of Scorichenko of the isomorphism between stable K-theory and functor homology for polynomial coefficients over an arbitrary ring.

Algebraic Topology · Mathematics 2009-09-01 Aurélien Djament

We prove exponential stability theorems of Nekhoroshev type for motion in the neighbourhood of an elliptic fixed point in Hamiltonian systems having an additional transverse component of arbitrary dimension.

Dynamical Systems · Mathematics 2012-01-19 Markus Kunze , David Stuart

In this work we construct from ground up a homotopy theory of C*-algebras. This is achieved in parallel with the development of classical homotopy theory by first introducing an unstable model structure and second a stable model structure.…

Algebraic Topology · Mathematics 2008-12-02 Paul Arne Østvær

We study stratification, that is the classification of localizing tensor ideal subcategories by geometric means, in the context of Kasparov's equivariant KK-theory of C*-algebras. We introduce a straightforward countable analog of the…

K-Theory and Homology · Mathematics 2026-01-21 Ivo Dell'Ambrogio , Rubén Martos

Let $A$ be a not necessarily commutative monoid with zero such that projective $A$-acts are free. This paper shows that the algebraic K-groups of $A$ can be defined using the +-construction and the Q-construction. It is shown that these two…

K-Theory and Homology · Mathematics 2010-09-17 Chenghao Chu , Jack Morava

In the founding paper on unbounded $KK$-theory it was established by Baaj and Julg that the bounded transform, which associates a class in $KK$-theory to any unbounded Kasparov module, is a surjective homomorphism (under a separability…

K-Theory and Homology · Mathematics 2020-08-25 Jens Kaad

This note consists of three unrelated remarks. First, we demonstrate how roughly speaking $*$-homomorphisms between matrix stable $C^*$-algebras are exactly the uniformly continuous $*$-preserving group homomorphisms between their genral…

Operator Algebras · Mathematics 2019-05-10 Bernhard Burgstaller

We revisit the construction of stable envelopes in equivariant elliptic cohomology [arXiv:1604.00423] and give a direct inductive proof of their existence and uniqueness in a rather general situation. We also discuss the specialization of…

Algebraic Geometry · Mathematics 2021-12-01 Andrei Okounkov

In this paper, we develop the theory of equivariant motivic homotopy theory, both unstable and stable. While our original interest was in the case of profinite group actions on smooth schemes, we discuss our results in as broad a setting as…

Algebraic Topology · Mathematics 2014-04-08 Gunnar Carlsson , Roy Joshua

We develop the foundations of $G$-global homotopy theory as a synthesis of classical equivariant homotopy theory on the one hand and global homotopy theory in the sense of Schwede on the other hand. Using this framework, we then introduce…

Algebraic Topology · Mathematics 2025-02-20 Tobias Lenz

We describe Universal Coefficient Theorems for the equivariant Kasparov theory for C*-algebras with an action of the group of integers or over a unique path space, using KK-valued invariants. We compare the resulting classification up to…

K-Theory and Homology · Mathematics 2020-11-04 Ralf Meyer

We study equivariant coarse homology theories through an axiomatic framework. To this end we introduce the category of equivariant bornological coarse spaces and construct the universal equivariant coarse homology theory with values in the…

K-Theory and Homology · Mathematics 2021-05-28 Ulrich Bunke , Alexander Engel , Daniel Kasprowski , Christoph Winges

The classical problem of algebraic models for homotopy types is precisely stated, to our knowledge for the first time. Two different natural statements for this problem are produced, the simplest one being entirely solved by the notion of…

Algebraic Topology · Mathematics 2007-05-23 Julio Rubio Garcia , Francis Sergeraert

This is half an overview article since what we describe here is essentially known. We describe $KK$-theory by generators and relations in a formal sum of formal products of $*$-homomorphisms and some synthetical morphisms. What comes out is…

K-Theory and Homology · Mathematics 2016-09-02 Bernhard Burgstaller

We study the question for which commutative ring spectra $A$ the tensor of a simplicial set $X$ with $A$, $X \otimes A$, is a stable invariant in the sense that it depends only on the homotopy type of $\Sigma X$. We prove several structural…

Algebraic Topology · Mathematics 2020-04-20 Ayelet Lindenstrauss , Birgit Richter

We establish axiomatic characterizations of $K$-theory and $KK$-theory for real C*-algebras. In particular, let $F$ be an abelian group-valued functor on separable real C*-algebras. We prove that if $F$ is homotopy invariant, stable, and…

Operator Algebras · Mathematics 2012-10-15 Jeffrey L. Boersema , Efren Ruiz

We classify invertible 2-dimensional framed and $r$-spin topological field theories by computing the homotopy groups and the $k$-invariant of the corresponding bordism categories. The zeroth homotopy group of a bordism category is the usual…

Algebraic Topology · Mathematics 2022-09-08 Lóránt Szegedy

For an \'etale correspondence $\Omega \colon G \to H$ of \'etale groupoids, we construct an induction functor $\mathrm{Ind}_\Omega \colon \mathrm{KK}^H \to \mathrm{KK}^G$ between equivariant Kasparov categories. We introduce the crossed…

Operator Algebras · Mathematics 2024-09-09 Alistair Miller