33 citations · 143 across the 27 of their papers we have counts for
15 papers · 1 filter
G-kernels and Crossed Modules
Sergio Girón Pacheco, Masaki Izumi, Ulrich Pennig
We develop a unified framework based on topological crossed modules for various lifting obstructions for -kernels. It allows us to identify actions, cocycle actions and -kern…
Spanier-Whitehead K-Duality and Duality of Extensions of -algebras
Ulrich Pennig, Taro Sogabe
KK-theory is a bivariant and homotopy-invariant functor on -algebras that combines K-theory and K-homology. KK-groups form the morphisms in a triangulated category. Spanier-Wh…
A survey on operator -theory via homotopical algebra
Ulrich Bunke, Markus Land, Ulrich Pennig
This is a survey article with the goal to advertise spectrum valued versions of - and - theory for -algebras via a (stable and symmetric monoidal) -categorica…
Computing cohomology groups that classify bundles of strongly self-absorbing -algebras
Marius Dadarlat, James E. McClure, Ulrich Pennig
Locally trivial bundles of -algebras with fibre for a strongly self-absorbing -algebra over a finite CW-complex form a group th…
Bundles of strongly self-absorbing -algebras with a Clifford grading
Marius Dadarlat, Ulrich Pennig
We extend our previous results on generalized Dixmier-Douady theory to graded -algebras, as means for explicit computations of the invariants arising for bundles of ungraded $…
Equivariant higher Dixmier-Douady Theory for circle actions on UHF-algebras
David E. Evans, Ulrich Pennig
We develop an equivariant Dixmier-Douady theory for locally trivial bundles of -algebras with fibre equipped with a fibrewise -action, where…
Deformations of Wreath Products
Marius Dadarlat, Ulrich Pennig, Andrew Schneider
Connectivity is a homotopy invariant property of a separable C*-algebra A which has three important consequences: absence of nontrivial projections, quasidiagonality and realizatio…
Connective C*-algebras
Marius Dadarlat, Ulrich Pennig
Connectivity is a homotopy invariant property of separable C*-algebras which has three notable consequences: absence of nontrivial projections, quasidiagonality and a more geometri…
Locally Trivial W*-Bundles
Samuel Evington, Ulrich Pennig
We prove that a tracially continuous W-bundle over a compact Hausdorff space with all fibres isomorphic to the hyperfinite II-factor that is…
Deformations of nilpotent groups and homotopy symmetric -algebras
Marius Dadarlat, Ulrich Pennig
The homotopy symmetric -algebras are those separable -algebras for which one can unsuspend in E-theory. We find a new simple condition that characterizes homotopy symmetr…
Crossed module actions on continuous trace -algebras
Ralf Meyer, Ulrich Pennig
We lift an action of a torus on the spectrum of a continuous trace algebra to an action of a certain crossed module of Lie groups that is an extension of $\mathbb{R}…
A Dixmier-Douady Theory for strongly self-absorbing C*-algebras II: the Brauer group
Marius Dadarlat, Ulrich Pennig
We have previously shown that the isomorphism classes of orientable locally trivial fields of -algebras over a compact metrizable space with fiber , w…
A Dixmier-Douady theory for strongly self-absorbing C*-algebras
Marius Dadarlat, Ulrich Pennig
We show that the Dixmier-Douady theory of continuous field -algebras with compact operators as fibers extends significantly to a more general theory of fields wit…
Quasi-multipliers of Hilbert and Banach C*-bimodules
Alexander Pavlov, Ulrich Pennig, Thomas Schick
Quasi-multipliers for a Hilbert C*-bimodule V were introduced by Brown, Mingo and Shen 1994 as a certain subset of the Banach bidual module V**. We give another (equivalent) defini…
The classification of non-local chiral CFT with c<1
Y. Kawahigashi, R. Longo, U. Pennig +1
All non-local but relatively local irreducible extensions of Virasoro chiral CFTs with c<1 are classified. The classification, which is a prerequisite for the classification of loc…