Twisted K-theory and finite-dimensional approximation

An approach toward a finite-dimensional definition of twisted K-theory

This is an expository account of the following result: we can construct a group by means of twisted Z_2-graded vectorial bundles which is isomorphic to K-theory twisted by any degree three integral cohomology class.

A model of the twisted $K$-theory related to bundles of finite order

In the present paper we propose a geometric model of the twisted K-theory corresponding to elements of finite order in $H^3(X, \mathbb{Z})\times [X, \BBSU_\otimes]$.

The nonvanishing first Hochschild cohomology of twisted finite simple group algebras

Let $G$ be a finite simple group and $k$ be an algebraically closed field of prime characteristic dividing the order of $G$. We show that for all $2$-cocycles $α\in Z^2(G;k^\times)$, the first Hochschild cohomology group of the twisted group algebra $HH^1(k_αG)$ is nonzero.

带扭曲系数的Chow群

Chow groups with twisted coefficients

本文推广Rost的Chow群定义至非挠性系数，计算多个有限群分类空间的扭曲Chow群，并揭示其与扭曲动机上同调之间的满射但非同构关系。

Twisted equivariant K-theory for proper actions of discrete groups

We give a construction for twisted equivariant K-theory in the case of a proper action of a discrete group using twisted bundles. Our construction uses results of Lueck and Oliver to extend a construction of Adem and Ruan. We also show the existence of a Chern character to twisted Bredon cohomology. This gives a partial answer to the question of when you can construct twisted equivariant K-theory out of finite rank twisted bundles.

Twisted K-theory, Real $\mathcal{A}$-bundles and Grothendieck-Witt groups

We introduce a general framework to unify several variants of twisted topological $K$-theory. We focus on the role of finite dimensional real simple algebras with a product-preserving involution, showing that Grothendieck-Witt groups provide interesting examples of twisted $K$-theory. These groups are linked with the classification of algebraic vector bundles on real algebraic varieties.