English
Related papers

Related papers: K-theory and formality

200 papers

Algebraic models for equivariant rational homotopy theory were developed by Triantafillou and Scull for finite group actions and $S^1$ action, respectively. They showed that given a diagram of rational cohomology algebras from the orbit…

Algebraic Topology · Mathematics 2025-09-24 Rekha Santhanam , Soumyadip Thandar

Let G be a finite group. We systematically exploit general homological methods in order to reduce the computation of G-equivariant KK-theory to topological equivariant K-theory. The key observation is that the functor assigning to a…

Operator Algebras · Mathematics 2016-05-11 Ivo Dell'Ambrogio

For T an abelian compact Lie group, we give a description of T-equivariant K-theory with complex coefficients in terms of equivariant cohomology. In the appendix we give applications of this by extending results of Chang-Skjelbred and…

Algebraic Topology · Mathematics 2009-03-10 Ioanid Rosu , Allen Knutson

In the mid 1980s, while working on establishing completion theorems for equivariant Algebraic K-Theory similar to the well-known completion theorems for equivariant topological K-theory, the late Robert Thomason found the strong finiteness…

Algebraic Geometry · Mathematics 2024-05-17 Gunnar Carlsson , Roy Joshua , Pablo Pelaez

In a previous paper, we have constructed, for an arbitrary Lie group G and any of the fields F=R or C, a good equivariant cohomology theory KF_G^*(-) on the category of proper $G$-CW-complex and have justified why it deserved the label…

Algebraic Topology · Mathematics 2010-11-02 Clément de Seguins Pazzis

In this paper, we construct an equivariant coarse homology theory with values in the category of non-commutative motives of Blumberg, Gepner and Tabuada, with coefficients in any small additive category. Equivariant coarse K-theory is…

K-Theory and Homology · Mathematics 2017-05-18 Ulrich Bunke , Denis-Charles Cisinski

In this book we prove unified classification results for equivariant principal bundles when the topological structure group is truncated. The conceptually transparent proof invokes a smooth Oka principle, which becomes available after…

Algebraic Topology · Mathematics 2022-08-17 Hisham Sati , Urs Schreiber

We apply results of Harada, Holm and Henriques to prove that the Atiyah-Segal equivariant complex $K$-theory ring of a divisive weighted projective space (which is singular for nontrivial weights) is isomorphic to the ring of integral…

Algebraic Topology · Mathematics 2015-02-10 Megumi Harada , Tara S. Holm , Nigel Ray , Gareth Williams

The proofs of K. Oka's Coherence Theorems are based on Weierstrass' Preparation (division) Theorem. Here we formulate and prove a Weak Coherence Theorem without using Weierstrass' Preparation Theorem, but only with power series expansions:…

Complex Variables · Mathematics 2018-07-24 Junjiro Noguchi

We study the $K$-theory and Swan theory of the group ring $R[G]$, when $G$ is a finite group and $R$ is any ring or ring spectrum. In this setting, the well-known assembly map for $K(R[G])$ has a companion called the coassembly map. We…

Algebraic Topology · Mathematics 2016-11-24 Cary Malkiewich

In this paper we study the "holomorphic K-theory" of a projective variety, which is defined in terms of the homotopy type of spaces of holomorphic maps from the variety to Grassmannians and loop groups. This theory was introduced by Lawson,…

Algebraic Topology · Mathematics 2007-05-23 Ralph L. Cohen , Paulo Lima-Filho

We introduce and study a $K$-theory of twisted bundles for associative algebras $A(\mathfrak g)$ of formal series with an infinite-Lie algebra coefficients over arbitrary compact topological spaces. Fibers of such bundles are given by…

Functional Analysis · Mathematics 2022-07-08 A. Zuevsky

Billey and Braden defined a geometric pattern map on flag manifolds which extends the generalized pattern map of Billey and Postnikov on Weyl groups. The interaction of this torus equivariant map with the Bruhat order and its action on line…

Algebraic Geometry · Mathematics 2016-03-15 Praise Adeyemo , Frank Sottile

This is a survey article with the goal to advertise spectrum valued versions of $K$- and $KK$- theory for $C^{*}$-algebras via a (stable and symmetric monoidal) $\infty$-categorical enhancement of Kasparov's classical $KK$-theory. The main…

Operator Algebras · Mathematics 2023-11-30 Ulrich Bunke , Markus Land , Ulrich Pennig

A. Vistoli proved a decomposition theorem for the rational equivariant algebraic K-theory of a variety under the action of a finite group $G$. We generalize his result to more general algebraic (co)homology theories having the Mackey…

Algebraic Geometry · Mathematics 2025-05-21 Francesco Sala

In this paper, we establish a theorem that proves a condition when an inclusion morphism between simplicial sets becomes a weak homotopy equivalence. Additionally, we present two applications of this result. The first application…

Algebraic Topology · Mathematics 2024-05-07 Hisato Matsukawa

We construct a symmetric spectrum representing the G-equivariant K-theory of C*-algebras for a compact group or a proper groupoid G. Our spectrum is functorial for equivariant *-homomorphisms. We use this to establish the additivity of the…

K-Theory and Homology · Mathematics 2011-04-19 Ivo Dell'Ambrogio , Heath Emerson , Tamaz Kandelaki , Ralf Meyer

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

In this paper, we define an invariant, which we believe should be the substitute for total K-theory in the case when there is one distinguished ideal. Moreover, some diagrams relating the new groups to the ordinary K-groups with…

Operator Algebras · Mathematics 2021-09-20 Søren Eilers , Gunnar Restorff , Efren Ruiz

For an arbitrary compact Lie group G, we describe a model for rational G-spectra with toral geometric isotropy and show that there is a convergent Adams spectral sequence based on it. The contribution from geometric isotropy at a subgroup K…

Algebraic Topology · Mathematics 2016-09-21 J. P. C. Greenlees