33 citations · 143 across the 27 of their papers we have counts for
27 papers
Infinite Loop Spaces and Group Actions on Strongly Self-Absorbing C*-Algebras
Ulrich Pennig, George Tridimas
Lifting obstructions for group actions, cocycle actions, and -kernels admit a cohomological description via topological crossed modules, as recently developed by Izumi, Giron-Pa…
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…
Computing Connection Matrices of Conley Complexes via Algebraic Morse Theory
Álvaro Torras-Casas, Ka Man Yim, Ulrich Pennig
Given a poset-graded chain complex of vector spaces, a Conley complex is the minimal chain-homotopic reduction of the initial complex that respects the poset grading. A connection…
Units of -equivariant -theory and bundles of UHF-algebras
Valerio Bianchi, Ulrich Pennig
We consider infinite tensor product actions of a finite cyclic group on the UHF-algebra for a finite-dimensional projectively faithful unit…
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…
Spectral Sequence Computation of Higher Twisted -Groups of
David E. Evans, Ulrich Pennig
Motivated by the Freed-Hopkins-Teleman theorem we study graded equivariant higher twists of -theory for the groups induced by exponential functors. We compute the ra…
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…
Interleaving Mayer-Vietoris spectral sequences
Álvaro Torras, Ulrich Pennig
We discuss the Mayer-Vietoris spectral sequence as an invariant in the context of persistent homology. In particular, we introduce the notion of -acyclic carriers and…
Equivariant higher twisted K-theory of SU(n) for exponential functor twists
David E. Evans, Ulrich Pennig
We prove that each exponential functor on the category of finite-dimensional complex inner product spaces and isomorphisms gives rise to an equivariant higher (ie. non-classical) t…
Exponential Functors, R-Matrices and Twists
Ulrich Pennig
In this paper we show that each polynomial exponential functor on complex finite-dimensional inner product spaces is defined up to equivalence of monoidal functors by an involutive…
Yang-Baxter representations of the infinite symmetric group
Gandalf Lechner, Ulrich Pennig, Simon Wood
Every unitary involutive solution of the quantum Yang-Baxter equation ("R-matrix") defines an extremal character and a representation of the infinite symmetric group . We…
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 noncommutative model for higher twisted K-Theory
Ulrich Pennig
We develop a operator algebraic model for twisted -theory, which includes the most general twistings as a generalized cohomology theory (i.e. all those classified by the unit sp…
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…
Unit spectra of K-theory from strongly self-absorbing C*-algebras
Marius Dadarlat, Ulrich Pennig
We give an operator algebraic model for the first group of the unit spectrum of complex topological K-theory, i.e. , by bundles of stabilized infinite Cu…
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…
Twisted K-theory and obstructions against positive scalar curvature metrics
Ulrich Pennig
We decompose the twisted index obstruction against positive scalar curvature metrics for oriented manifolds with spin universal cover into a pairing of a twisted -homolog…