Higher index theorems and the boundary map in cyclic cohomology.
Homological index formulas for elliptic operators over C*-algebras.
Homotopy invariance of higher signatures and -manifold groups
For closed oriented manifolds, we establish oriented homotopy invariance of higher signatures that come from the fundamental group of a large class of orientable -manifolds, including the “piecewise geometric” ones in the sense of Thurston. In particular, this class, that will be carefully described, is the class of all orientable -manifolds if the Thurston Geometrization Conjecture is true. In fact, for this type of groups, we show that the Baum-Connes Conjecture With Coefficients holds. The...
Homotopy invariance of relative eta-invariants and -algebra -theory.
Index pairings for pullbacks of C*-algebras
In this overview, we study how to reduce the index pairing for a fibre-product C*-algebra to the index pairing for the C*-algebra over which the fibre product is taken. As an example we analyze the case of suspensions and apply it to noncommutative instanton bundles of arbitrary charges over the suspension of quantum deformations of the 3-sphere.
Induced subsystems associated to a Cantor minimal system
Let (X,T) be a Cantor minimal system and let (R,) be the associated étale equivalence relation (the orbit equivalence relation). We show that for an arbitrary Cantor minimal system (Y,S) there exists a closed subset Z of X such that (Y,S) is conjugate to the subsystem (Z,T̃), where T̃ is the induced map on Z from T. We explore when we may choose Z to be a T-regular and/or a T-thin set, and we relate T-regularity of a set to R-étaleness. The latter concept plays an important role in the study of...
Iterating the Pimsner construction.
- and -theory of the semi-direct product of the discrete 3-dimensional Heisenberg group by .
-equivalence and continuous bundles of -algebras.
-theory as the -theory of -categories.
-théorie algébrique négative et -théorie topologique de l’algèbre de Fréchet des opérateurs régularisants
-theory and Toeplitz -algebras a survey
KK-theory of the full free product of unital C*-algebras.
K-theory from the point of view of C*-algebras and Fredholm representations
These notes represent the subject of five lectures which were delivered as a minicourse during the VI conference in Krynica, Poland, “Geometry and Topology of Manifolds”, May, 2–8, 2004.
K-theory of Boutet de Monvel's algebra
We consider the norm closure 𝔄 of the algebra of all operators of order and class zero in Boutet de Monvel's calculus on a compact manifold X with boundary ∂X. Assuming that all connected components of X have nonempty boundary, we show that K₁(𝔄) ≃ K₁(C(X)) ⊕ ker χ, where χ: K₀(C₀(T*Ẋ)) → ℤ is the topological index, T*Ẋ denoting the cotangent bundle of the interior. Also K₀(𝔄) is topologically determined. In case ∂X has torsion free K-theory, we get K₀(𝔄) ≃ K₀(C(X)) ⊕ K₁(C₀(T*Ẋ)).
-index theorems, KK-theory, and connections.
Le théorème de l'indice relatif
Matrices of positive polynomials.
Matsumoto -groups associated to certain shift spaces.
Non-commutative differential geometry