61 citations · 438 across the 47 of their papers we have counts for
9 papers · 1 filter
Index Theory for Boundary Value Problems via Continuous Fields of C*-algebras
Johannes Aastrup, Ryszard Nest, Elmar Schrohe
We prove an index theorem for boundary value problems in Boutet de Monvel's calculus on a compact manifold X with boundary. The basic tool is the tangent semigroupoid $\cT^-X$ gene…
Fibrations with noncommutative fibers
Siegfried Echterhoff, Ryszard Nest, Herve Oyono-Oyono
We study an analogue of fibrations of topological spaces with the homotopy lifting property in the setting of C*-algebra bundles. We then derive an analogue of the Leray-Serre spec…
Principal noncommutative torus bundles
Siegfried Echterhoff, Ryszard Nest, Herve Oyono-Oyono
In this paper we study continuous bundles of C*-algebras which are non-commutative analogues of principal torus bundles. We show that all such bundles, although in general being ve…
C*-Algebras over Topological Spaces: Filtrated K-Theory
Ralf Meyer, Ryszard Nest
We define the filtrated K-theory of a C*-algebra over a finite topological space X and explain how to construct a spectral sequence that computes the bivariant Kasparov theory over…
Deformations of algebroid stacks
Paul Bressler, Alexander Gorokhovsky, Ryszard Nest +1
In this paper we consider deformations of an algebroid stack on an etale groupoid. We construct a differential graded Lie algebra (DGLA) which controls this deformation theory. In…
Twisted cyclic theory, equivariant KK theory and KMS States
Alan L. Carey, Sergey Neshveyev, Ryszard Nest +1
Recently, examples of an index theory for KMS states of circle actions were discovered, \cite{CPR2,CRT}. We show that these examples are not isolated. Rather there is a general fra…
A new spectral triple over a space of connections
Johannes Aastrup, Jesper M. Grimstrup, Ryszard Nest
A new construction of a semifinite spectral triple on an algebra of holonomy loops is presented. The construction is canonically associated to quantum gravity and is an alternative…
On Spectral Triples in Quantum Gravity II
Johannes Aastrup, Jesper M. Grimstrup, Ryszard Nest
A semifinite spectral triple for an algebra canonically associated to canonical quantum gravity is constructed. The algebra is generated by based loops in a triangulation and its b…
On Spectral Triples in Quantum Gravity I
Johannes Aastrup, Jesper M. Grimstrup, Ryszard Nest
This paper establishes a link between Noncommutative Geometry and canonical quantum gravity. A semi-finite spectral triple over a space of connections is presented. The triple invo…